Physics Jokes 3

8/6/2019 Physics Jokes 3

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MEASURE THE HEIGHT OF A BUILDING WITH HELP OF A BAROMETER

1: Go to the top floor, tie a long piece of string to the barometer, let it down 'till it

touches the ground and measure the length of the string.

The examiner wasn't satisfied, so they decided to interview the guy:

"Can you give us another method, one which demonstrates your knowledge ofPhysics ?"

2: "Sure, go to the top floor, drop the barometer off, and measure how long beforeit hits the ground......"

"Not, quite what we wanted, care to try again ?"

3: "Make a pendulum of the barometer, measure its period at the bottom, thenmeasure its period at the top......"

"..another try ?...."

4: "Measure the length of the barometer, then mount it vertically on the ground ona sunny day and measure its shadow, measure the shadow of the skyscraper....."

"....and again ?...."

5: "walk up the stairs and use the barometer as a ruler to measure the height ofthe walls in the stairwells."

"...One more try ?"

6: "Find where the janitor lives, knock on his door and say 'Please, Mr Janitor, if I

give you this nice Barometer, will you tell me the height of this building ?"

There are many more ways, for instance:

7: To which the less polite alternative is to threaten to wallop the caretaker withthe barometer unless they tell you how high the building is. The just-releasedbook, "Expert C Programming (Deep C Secrets)", Peter van der Linden,SunSoft/Prentice-Hall, ISBN 0-13-177429-8, lists twenty-one (21) more or lessuseful ways to measure the height of a building with a barometer.

8: Use the barometer as a paperweight while examining the building plans.

9: Sell the barometer and buy a tape measure.

10: Use a barometer to reflect a laser beam from the top and measure the traveltime.

11: Track the shadow of the building positioning a barometer on the ground every

hour.


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12: Create an explosion on the top and measure the time for the pressuredepression indicated on the barometer.

13: For fun, how about using sound; fire a starting pistol at the bottom, time thedifference of arrival at the top. About a second for the Empire State building, andof course it'd have to be a damn great gun to carry over the howl and screech ofdowntown Gotham. Also, the detonation might get confused with the sounds ofroutine crack dealing below.14: Here's one no-one seems to have thought of :1) Build a sandpit (full of sand, OK?) at the bottom of the building.2) Rake the sand flat.3) Drop the barometer from the top of the building into the sand.

4) Measure the average diameter of the crater thus created.5) From the answer to (4), the mass of the barometer and the properties of thesand (viscosity?) calculate its impact speed and thus the height from which it wasdropped.

Also has the advantage that you may get your barometer back intact if:a) The building is small.b) The sand is soft.c) The barometer is light and strong.

P.S. Watch out for wind-affected drops hitting pedestrians from tallbuildings...

15: 1) Borrow one of those fancy two channel digital oscilloscopes from somebody'slab when they aren't looking.2) Connect a microphone to each channel. Place one microphone on ground level. Callit "A".3) Place other microphone "B" at top of building, directly over the firstmicrophone. Note that you may need a lot of cable.4) Place barometer as close to A as possible.5) Set scope to trigger on channel A.6) Whack barometer once with hammer or suitable object. The purpose of this isto make a nice, sharp impulse.7) Measure the difference in arrival time of the impulse in each channel. This ishow long it took the sound to travel to the top of the building. The speed of soundis approximately 1 foot per millisecond under most conditions, so we can find thedistance travelled by the pulse and thus the height of the building.

Now don't even get me started about using a microphone, an oscilloscopeand audible "clicks" to make an acoustical motion detector. :)

Except for the trivial method (2), there are other ways to use droppingthe barometer:

16: Drop the barometer off the building onto someones head, killing themoutright. Wait for the next day's papers and read the part where is says "Aman (39) was killed yesterday when a scientist (26) dropped a barometer

from the top of an [x] foot building".


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17: If it's a _tall_ building, one could drop the barometer, measure how muchits length had changed when it reached the bottom, work out the speed fromthe relativistic dilation, and form that nd knwon gravitational acceleration

calculate the height..

18: Actually, you don't have to drop it to use relativity.just hold itparallel to your speed vector (as you rotate with the world) and measurethe length. do this at the top and at the bottom of the building; at thetop, being further from the centre of the world, the speed is greater andcan be determined by the dilatation of the length of the barometer. fromthere, it's easy to find out just how much further from the centre you are;this figure being the height of the building.

19:1) Make sure your barometer contains alcohol[1].2) Spill the alcohol over a heap of wood, paper and other inflammablestuff in the cellar of the building in question.3) Ignite.4) Get out.5) Listen to a local station on your radio.6) If all works fine, you will hear a message like

"A fire broke out in the feet tall in ..."

7) There you are.8) "And now the police asks for your cooperation in connection withthe fire in the today:A young man carrying a broken barometer has been seen leaving thebuilding right before the fire was detected. Description asfollows:..."

DISCLAIMER: Don't try this at home. It's far too obvious.

20:1) Measure the length of the barometer.2) Borrow the scaffolding from the window washers.3) Place the bottom of the barometer on the ground and make apencil mark on the building at the top of the barometer.4) Raise the scaffolding a bit to facilitate barometer and pencil

manipulation.5) Place the bottom of the barometer at the pencil mark on thebuilding from step 3 and make a mark on the building at the top of thebarometer.6) Repeat steps 4 and 5 until you reach the top of the building.Be sure to count the pencil marks as you go. If at the top of thebuilding, you end up with the barometer sticking up above the buildingthen you must follow the special steps noted later and add that to youranswer.


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7) Multiply the number of barometer lengths by the length of thebarometer to get the building height.

*****SPECIAL STEPS NOTED HERE*****

s1) Holding the end of the barometer at the top of the last fullbarometer length mark, rotate the other end of the barometer until it isin line with the top of the building.

s2) Measure the angle between verticle and the barometer.

s3) Take the cosine of that angle.

s4) Take the answer to s4 and add that to the number of fullbarometer lengths measured and multiply by the length of the barometer.

**********************************

Note: For best results, always hold the barometer vertically.

21: (Aneroid barometers only) Lie the barometer on its back on the ground.Bounce a laser off the glass front and time how long that takes. Subtractthe thickness of the barometer.

22: (Mercury barometers only) Drain the mercury out and put it in a bowl.Bounce a laser off the surface of the mercury, etc. etc. etc. Again,subtract the height of the surface.

23:1. Take the glass tube out of the barometer.2. Attach one end of the glass tube to the top of the building,

so that the other end points directly downwards.3. Measure the time difference between step 2. and the other end

of the glass tube touching the ground with a high-precisiontiming device.

4. Calculate the height of the building using the known viscosityof glass.

24: Run a transparent tube up the side of the building. Fill it with water,seal the top and open the bottom inside a reservoir of water. I.e.effectively make a water barometer - just like a mercury barometer, but

with water instead of the mercury.

Wait for a day when the water level matches the height of the building, andread off the atmospheric pressure on your original barometer. Calculate theheight of water that this atmospheric pressure can support.

Unless your building is pretty close to 10 meters high, you may have to waita long time.


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25 :Alternatively you could use fluids with different densities until youfound one which was the height of the building.Remember you have to seal the top of the tube, and remove all air from itfor an accurate reading.

26:1) Beat on the foundation o the building, using the barometer, until the

building comes crashing down.2) Any sizeable pieces should be pulverized into pebbles and dust.3) The height of the building should be zero. If not, repeat step 2.

This method may require more than one barometer. Make sure that you buythe same kind, for a more scientific study.

27: Remove the glass pipe from the barometer. Attach one end to an arrow andthe other to the top of the building. Evenly heat up the middle of the tubeto red heat and fire the arrow at the ground with a bow.Measure the width of the extended glass tube at several points and average.Knowing the original width, work out the distance travelled by the arrow.Measure the distance of the arrow from the base of the building.Use trigonometry to calculate the height of the building.

28: As a quick check, using the mercury you removed from the barometer:Measure the temperature of the mercury at the top of the building, and putit in a perfectly insulating container. Drop it off the building and measurethe temperature of the mercury after it has landed. Calculate the energygained and therefore the height of the building.

29: Sellotape a tuning fork to the barometer and whack it just before youthrow the barometer off the building. Measure the doppler shift at themoment of impact to get its velocity and, hence, the height of thebuilding.30: Wait untill Hell freezes over. Extrude the mercury into a wire.Use wire to measure the building.

31:1) Set the barometer a measured distance from the building, ensuring aclear line-of-sight exists between it and both the top and base of thebuilding.2) Buy, borrow or steal a theodolite.3) Measure the angles (from horizontal) from the base and the top of the

building to the barometer.4) Diagram the distances and angles at a 1:1 scale on a really big pieceof paper.5) Lay out the diagram on a convenient empty parking lot.6) Pace off the distance in question.

32: Tie a copper barometer to a copper wire of known diameter. Lowerbarometer from roof until it just rests on the ground. Apply aknown voltage between the barometer and the end of the wire at root

level. Measure current flowing between these two points and divide


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this number into the voltage, giving you the resistance of thebarometer/wire combination. Subtract the barometer's resistance anduse the resistance of the wire to determine its length. Add back inthe height of the barometer.

Also, I'd like to see some answers formulated using a bungee jumpingbarometer. Possibly using the thickness of the bungee cord with thebarometer at ground level, maybe using the barometer weight necessaryto stretch the bungee cord all the way to the ground, etc...

Every meteorological observation site should have at least onebungee jumping barometer. At least.

33: Read the inscription on the plaque on the back of the barometer,which says,"This barometer is the property of the metres high building. Please do not remove." [1]

34: Okay, one more idea which was given to me by my graduate researchadvisor. Suspend the barometer from the top of the building witha wire. Remove the barometer and measure the change in length ofthe wire. With the weight of the barometer and Young's modulusfor the wire, one can calculate the length.

35:1. Look for Godzilla.2. Wait until he stand before the building.3. Poke him with the barometer in the,eh,backside.4. YEOWCH!SLAM!PLOFF!5. Now that the house is overturned (I think you callit a "flat" :-) , the task has turned into measuringthe length, which is much more convenient.

And then there is trigonometry, gravity force differentials, laserrangefinding.....and the list goes on.

36: Heres my silly [1] attempt at answering the question of how tall abuilding is, using a barometer. One can easily find the height of abuilding, simply by finding its top, and working from there.

Find a person with vertigo. (fear of heights)

Give them the barometer.

Tell them to put it on top of the building.

we have several measurements, which can then be cross referenced todetermine the height of the building.


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1. Measure the volume of the sound caused by the persons kneesknocking together. The taller the building, the louder the knocking.This should be standardised first, by testing the sound produced forbuildings of known height.

2. attach electrodes to your subject. measure the EEG reading at themoment immediately after placing the barometer on top of the building.(ie, the moment they look down) amplitude of waves indicates anxiety.Again, standardisation should be done to ensure accuracy. [2]

3. Measure the depth of the crater created when they land, afterhaving seen how high they were when they put the barometer on top ofthe building.

Silky...in an attempt to be as perverse as possible. [3]

[1] well everyone else has.[2] a flat line is the exception to the rule here.[3] no, not pervert.

37: Take the barometer to the top of the building. At the base of thebuilding put a trigger that when the barometer is dropped onto it, it emitsa loud, high frequency noise. Start stopwatch once the trigger isactivated. Put an audiometer at the top of the building to stop thestopwatch when the audiometer is activated (at least activated higher thanthe backround noise already present). Determine from there the speed ofsound (for that particular day) and therefore determine the top of thebuilding.

38:I think the best procedure must be:a) Locate a university where a physics exam or test is about to begin.

b) Locate a student waiting for this test.

b) Impose as a physics professor (wear silly clothes, talk funny,mess up your hair, etc) and lure the student into a separate room.

c) Show the barameter you brought with you to the student and ask himthe following question: "You are given an accurate barometer, how would

you use it to determine the height of a skyscraper ?". Try to squeeze asmany answer out of him as possible.

d) If you didn't get any useful answers from c), then try to post thequestion on Internet, preferably in a news group or on a web-page.

39: Find a barometer with heights of local buildings on itGo to all the local gift shops. Look for a fancy souvenir barometer,the kind which shows important local landmarks. Find one which showsthe heights of local buildings and considers this building importantenough to be listed. Use this barometer.


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40: Drop the barometer on the roof and on the groundHold the barometer straight in front of you and drop it. Measure, verycarefully, how long it takes to hit the ground. Go up on the roof andhold the barometer in the same position. Drop it and measure, again

very carefully, how long it takes to hit the roof. Since gravity fallsoff as the square of the distance from the centre of the planet, youcan use the difference in times to calculate the height of thebuilding relative to the distance from the base of the building to thecentre of the planet. The local library can provide you with thedistance to the centre of the planet in the required units.

Note: The ratio of the times is the same as the ratio of the distancesfrom the drop points to the centre of the planet.

41: Drop (and shatter) the mercury barometer at the base of the buidlingon a windless day. Measure the increase in the mercury vapourconcentration at the top of the building. Solve the diffusion equationto determine the distance from the shattered barometer to the top ofthe building.

42: Place the barometer on the ground floor of the building. Seal all thebuilding's doors and windows. Fill the building with water. Read thepressure measurement from the barometer. This gives the weight of a columnof water the same height as the building. Use this and the ratio of thedensity of mercury to the density of water to calculate the height of thebuilding.

Note: It is common courtesy to evacuate the building before using thistechnique.

43: If you have access to an airless world, take the building there. Throwthe barometer horizontally off the building. If the barometer hits theground, retrieve it and try again, throwing harder. The objective is tothrow it hard enough to achieve a circular orbit. Once the barometer is inorbit around the planet, you can measure the period of the orbit. Comparethis with the period of the orbit when you throw the barometer from thebase of the building. Use this ratio and Kepler's laws to determine theheight of the building (relative to the radius of the planet).44:(1) Get a barometer that uses a dial for the reading.(2) Open the barometer and remove the mechanisim to allow the hand to

swing freely.(3) Dig a hole and climb in, hold the barometer at ground level and

point it at the top of the building.(4) Use the barometer as a sextant and measure the angle of inclination,

then pace off the distance to the building and use trig to calculatethe height of the building.

45:(1) Get an assistant, two synchronized clocks, some gas and a match.

(2) Assistant remains at the base of the building and you go to the top.


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(3) Assistant covers barometer with gas and at a predetermined time,lights barometer with match.

(4) You time when you see the flash, and calculate the distance giventhe speed of light.

46:(1) Go to the top of the building.(2) Drop barometer off building and start timer.(3) Stop timer when you hear barometer hit the ground(4) Solve for height taking into account gravatational acceleration and

the speed of sound.47:Go to the barometers manufacturer and tell him you want a barometer as high

as the building in question. the manufacturer will say something like:"what the fuck do you need a XXX feet long barometer for"48:Tie barometer to a yardstick. Stack many yardsticks together(head to head).Measure inches.49:Assume that the barometer has a rectangular shape. It therefore must havea corner. If we also assume that we are finding the height of the buildingfor a professor on a test, then we must also assume that he has an answeralready prepared to compare to the students answers. Since the entireclass has to solve this question, every student has a barometer. Stealsome other students barometers, sell them for a ski mask. Wear the skimask to the professor's house, and threaten him with the pointy corner ofthe barometer. Force him to give the correct answer, then use the correctanswer.50:1. Weigh the barometer at the ground floor of the building (W).2. Take the elevator to the roof and weigh the barometer a second time (w).

3. The height of the building H is given byH=R*(sqrt(W/w) -1) R~=6378140 m.

51:Take barometer & hammer very flat & thin.Construct large box from barometer & place over building.From Schroedingers principle, we can now say that the state of the is unknown (soany answer will be correct!)

52:1)Find mass of the barometer 2)weigh the barometer on the ground 3)weigh thebarometer on the roof 4)use F/M=g to find two different gs 5)use g=GMm/r^2 tofind two radii 6)subtract

53:Drink the Mercury. When you die you'll go to heaven where all things are revealedincluding the height of the building.

54:Gather 100 friends. Have each of them guess at the height of the building 100


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times. This gives a sample size of 10000. Calculate your sample mean Xn and samplevariance s^2. Since the sample size is large, s^2 approximates the true variance.Use Xn -Z(s^2)/100 < height < Xn + Z(s^2)/100 to construct a 1-alpha probabilityinterval for the height of the building. Alternatively, have your 100 friends guess

at the height n times. Calculate the sample mean each time. As n goes to infinity,the various sample means follow a normal distribution with mu = true height ofbuilding. Either way, use the beat your 100 friends over the head with thebarometer so your professor cannot claim you had outside help.

55:A rather advanced solution would be attaching a medium powered transmitterwithin the barometer. Now measure the received power in a dipole antenna with amicro-voltmeter, when the barometer is on the top of building. Now take thebarometer to ground level and then measure the received power. The difference inreceiving power will indicate the loss due to attenuation which is proportional toheight of the building.

56:Take the barometer to the wizard of Oz. He will put some courage into it as well assome brains. Now ask the barometer to jump from the top of building. If you give astop-watch to that barometer it will easity find the height of building.

57:

This solution works in zero gravity conditions, and assuming that the barometerand the building have equal weight. First perform pirouette like action as a balletdancer without holding anything for 10 sec. and note the number of rotations. Nexttry it while holding a barometer with outstreched arms, note the rotations in 10sec. Finally hold the building and perform the same thing. The moment of inertiadepends on the radius. I think this much clue is enough, you can solve the rest!

58:Go to top of building without barometer and with accurate weighing scales. Weigh

self. Then place barometer at the base of the building, go back to the top andweigh self again. The increase in weight due to the gravitational attraction of thebarometer can be used (knowing the mass of the barometer) to calculate theheight of the building.

59:Mass the barometer. Ideally, the building has an elevator. If not, you can use thestairs, but it becomes more difficult to be accurate. Use the barometer in a lewdstreet comedy show, so that you can earn a few dollars to buy a scale, and a videocamera. (Or, if you are very good, a stop watch, and just paper and pencil.) Go tothe ground floor of the building, and get in the evelator. Start recording the scalewith the video camera. If the scale does not read 0, you can use this as a clibrationfactor. Put the barometer on the scale. Take the elevator to the top floor(stopping at each along the way). (If the top floor is not directly accessible, gooutside, look at the building, and determine which floor is half way up to the top.Multiply final answer by two) Since we stopped at each floor along the way, we havea pretty good idea what acceleration due to gravity is at various points along theelevator ride We can interpolate the spaces between sample points. Now, sinceinitial velocity was zero, and we know the acceleration at every point in the trip

(displayed weight = m*(acceleration due to gravity + acceleration due to elevator)),


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we can go frame by frame along the recorded video tape, and numerically integratethe acceleration to get velocity, and then position at each point in time. Theresulting position at the end of the tape is the height of the building. Return scaleto store to get money back. (Which I actually did for a physics project one time...

We kept the scale in the packaging for the entire experiment. My two female labpartners and I then went back to the store, and said it didn't match ourbathroom.)

60:Extract the mercury from the barometer. Take an accurate mass measurement ofthe mercury sample. Take it to your neighborhood atomic pile. Bombard themercury with neutrons in the highest flux region of the core for, oh, about a week.The mercury is now quite radioactive. Determine exactly how radioactive using thecommon activation equation. Remove the mercury from the core, and mount themercury sample at the top of the building. (You may wish to do this remotely.....)Now use a well-calibrated radiation detector to determine the gamma ray doserate at the bottom of the building. Use the normal radiation dose equations (withappropriate buildup factors for building material and surroundings) to determinethe height of the building. (As we all know, radiation dose from a point source fallsoff as the inverse square of the distance.) Do not forget to correct for the decayof the radiomercury atoms during the time it takes to perform the experiment.

From: "Douglas Grimm"

61: Tie a long piece of string to the barometer. Hold one end of thestring from the top of the building, so that the end of the barometerbarely clears the ground. Give the barometer a small displacementand time its period as a compound pendulum.

62: Smash the barometer on the roof of the building and time howlong it takes for the mercury to drip down the wall of the building tothe ground. Use the known viscosity of mercury to find the velocity.

63: Throw the barometer horizontally off the building with a knownvelocity (calibrate your throwing ability by timing and measuringbarometer throws on the ground). Use projectile motion to find theheight of the building once the distance the barometer lands fromthe building is found.

64: Find a small, very efficient, very light electric motor. Weigh thebarometer. Use the motor to carry the barometer up the building.Using a voltmeter and ammeter, calculate the work done by the

motor, and thus the gravitational potential difference between the topand bottom of the building. Knowing g, find the height.

65: Go to the basement. Find a part of the basement such thatdirectly above you is solid brick until you reach the roof. Throw thebarometer at the ceiling of the basement, which is the floor of thebuilding. The barometer will most likely bounce off the floor. Repeatn times, where n is a very large number. In a few trials, thebarometer will tunnel through the potential field of the bricks, and

appear on the top of the building. Calculate the percentage of trials


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for which the barometer tunnels. Use the quantum tunnelingequation to calculate the length of the barrier, and thus the height ofthe building. Note: this effect can be calibrated properly by findingthe likelyhood of the barometer tunneling through one brick.

66: Attach a copper wire to the top of the building, and attach theother end to the ground. Smash the barometer and use one of theshards of glass to cut the wire halfway up the building andplace an ammeter in series with the wire. Knowing the currentthrough the wire and the resistivity of copper, the potentialdifference between the top of the building and the bottom of thebuilding can be found. This will be a gravitational potentialdifference, not an electrical one, but the electrons don't know that.

Thus, since g is known, the height of the building can be found.

67: Find a large wooden rod a bit longer than the building is high.Wrap an insulated copper wire around this rod at a uniform turndensity. Make the coil stop at the top and bottom of the building.Run alternating current through the coil, measure current andvoltage, and determine the inductance of the coil. Place thebarometer in series with the coil so the resistance of the circuit isenough to stop the wires from melting. With the inductance of thecoil and its turns per unit length and radius, the length of thecoil, and thus the height of the building, can be found.

68: Drop the barometer off the top of the building and measure theradius of the resulting puddle of mercury.

69: Using a device that can propel an object at a known velocity(such as a baseball pitching machine or a rail gun), find the escapevelocity of the barometer from the ground, after first having tied astring to the barometer so it can be retrieved from deep space.Repeat on the top of the building. The difference in escape velocityenergies gives the gravitational potential difference between theground and the roof, thus yielding the height.

70: Using the aforementioned pitching machine or rail gun, find thevelocity at which the barometer needs to be projected to reach theroof from the ground.

71: Make a small hole in the barometer through which mercury drips

at a constant rate. Time this rate at the ground. Place the barometeron the roof and observe the drip rate from the ground withbinoculars. The drip rate will be dilated, by general relativity, by afactor which will give the difference in the curvature of space at thebottom and top of the building. Knowing the mass and radius of theearth and so on, the height of the building can be found.

72: THIS METHOD USES MORE THAN ONE BAROMETER: Packas many barometers as possible into the building until it undergoes

gravitational collapse and becomes a black hole. Knowing the


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number of barometers used, the mass of this hole can becalculated, and the Schwarzchild radius of the hole is thus half theheight of the building.

73: Find a barometer that uses a liquid with no surface tensionwhatsoever (superfluid helium?). Break the barometer and spreadthe liquid evenly over the surface of the building. Measure the depthof the resulting liquid film. Knowing the volume of the barometer, thisgives the surface area of the building, which will give its height,if its width and depth are known.

74: Stand on the roof of the building. Throw the barometer to a pointexactly on the horizon. Measure the distance from the bottom of the

building to the barometer. This gives the horizon distance at the topof the building, thus giving its height above the ground.

75: Make a small hole in the barometer so mercury drips out at aconstant rate. Place the barometer so that it is dripping off theroof onto the ground. Measure the time between a drop beingreleased from the barometer and the drop hitting the ground. Repeatthe measurement when moving towards the ground at a knownvelocity. The time between a drop being released and a drop hittingthe ground will change. Using the Lorentz transformation equationsand taking the top of the tower as x = 0, the position of the groundcan be found. This will yield the height of the tower.

76: Find a steel cable. Attach it to the barometer and use thebarometer as a physical pendulum to measure g. Then attach thebuilding to the cable (after having remove it from its foundationsand attaching the cable to a crane of some sort), and using thebuilding as a physical pendulum, and knowing g, measure itsmoment of inertia. This will give the dimensions of the building andso on.

77: Use a barometer containing sulfuric acid. Break the barometeron the roof of the building and time how long it takes the acid to eatits way down to the ground.

78: Measure the volume of the barometer at the bottom and top ofthe building. By knowing the coefficient of thermal expansion ofglass, the temperature difference between the top and bottom can

be calculated. Refer this to known data of atmospheric temperatureas a function of height.

79: Every time somebody walks into or out of the building, stab themwith the sharpened end of the barometer (after having sharpened it,of course). Word of the 'Barometer Murderer' will eventually reachthe building's owner, who will of course be forced to sell the building.The real estate advertisement should give the height of the building.

80: Knowing the density, width and length of the building, rip the


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building from its foundations and place it on top of the barometer,giving it a pressure equal to the building's weight divided by themeasurement area of the barometer. Thus the weight, and so theheight, of the building can be found.

81: Find the architect who designed the building, crack the(mercury) barometer over his coffee, watch him die when he drinksit, then steal the building's specifications, including height.

82: THIS ALSO REQUIRES MORE THAN ONE BAROMETER:knowing Young's Modulus for brick, place barometers on the roofuntil the roof is lowered by one barometer length. This change in theheight of the building under a known stress and Young's Modulus will

give the height of the building.

83: Place a cat on top of the building. Prod it with the barometer sothat it falls off the roof. See whether the cat dies when it hits theground. Repeat n times, where n>>{a large number}. Refer to DrKarl Kruszelnicki's paper on the probability of a cat dying whenfalling from a certain height.

84: AGAIN, MORE THAN ONE BAROMETER: place as manybarometers in the building as will fit. This gives the volume, thus theheight, if other dimensions are known.

85: Use a machine (such as the aforementioned baseball pitchingmachine or rail gun) that can hurl the barometer down from theground into a hole in the ground at a velocity that is only known towithin a certain tolerance. Find the smallest uncertainty in velocity,and thus momentum, such that the barometer appears on top of thebuilding. Use Heisenburg's position-momentum uncertaintyrelationship to find the height of the building.

86: Tie a string to the barometer and hang it as a plumb bob. Thestring will be slightly deflected from the vertical by the gravitationaleffect of the building. This gives the mass of the building, etc.

87: Find at what velocity you must move upwards or downwards pastthe building such that the building is contracted to the same lengthas the barometer. Find gamma for this velocity, multiply by thelength of the barometer.

88:Measure the color of the barometer.Drop the barometer off the building.Measure color doppler at the moment of impact.From there extrapolate the velocity at impact.Finally use the gravity exuation to figure the height of the building.

89:Drop barometer

Measure radius of the debris field


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This should be a function of velocity hence the height of the building.

90:Place barometer in such a way that a rock will roll out and push whoever

grabs the barometer off the building.Wait for newspaper reports about the buildings height.

91: Mount the barometer to top edge of building. Use a projectile weaponfrom a fixed location to shoot it. Using ballistic curve and weapon specs,calculate height of building.

92: Using barometer as a pointer, count the number of floors in building,and calculate the total height using the standard height of a storey of

that type of building. Or count bricks if you need to.

93: Measure the base of the building in barometer lengths. Measure theangle to the base corner to the diagonally opposite top corner. Use Trigto calculate unknown height of triangle.

94: Sell the barometer, put the money in an fee-free long term account.Put yourself in suspended annimation until the compound-interest on yourmoney makes you the richest man on earth, then use this money to capitalize

your plans for world domination. Then when you are the Almighty SupremeMaster of the Entire Universe, order one of your lackeys to report back youwith the height of that building. Or you could have the stupid thingknocked down if you wanted to ...

95: Get some electronic parts, and a block of plasticine, stick the parts,and some coiled wires into the plasticine, and mount the barometer to this.Put a sticker on the plasticine, that has, "C4", or "SEMTEX", written inclear, signal yellow lettering.Go to your local airport and highjack an aircraft, explaining that you

will detonate this device unless the pilot does exactly as told, (you canembroider this performance any way you wish ... eg. Wear a towel on yourhead and see if you can start a Middle-Eastern war. Or maybe you couldhave some more selfish demands like $50 000 000 in small unmarked bills, ormaybe demand that Roseanne Barr, be forced to give up acting, you know -whatever you like).Anyway, where was I? So you instruct the pilot to fly directly past the

building at roof level, and as you pass it, simply look at the altimeter.Ask the pilot if there are any calibration ajustments and then work out the

building height.After this you can tell everybody the truth about the barometer and the

bomb, and you can have a jolly good laugh about it and maybe get togetherafterwards for a social drink, or something.96: ComedianAsk a comedian. apparently comedians are the worlds foremost experts onusing barometers to measure heights. Actually I would really like to knowhow to measure the height of a building with a rectal thermometer.


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97: BusinessmanCreate a small company selling barometers. Sell stock in the company.Advertise the many benefits of barometers on daytime TV. Everybody needs abarometer. They are the best thing since sliced bread. They chop. They

slice. They dice. Get the ginsu barometer. Now only $19.99. You get theadded bumper sticker that says "my parents went to Florida and all I gotwas this lousy barometer".Diversify your product by producing a full line of models, the economybarometer, the standard barometer and the super-duper-extra-deluxebarometer with vernier caliper and laser scope for high precisionmeasurements.Initiate a telemarketing program that calls people late at night askingthem to buy barometers.

Bribe all the physics professors at the university to ask thier studentsthis stupid question on their exams. When the stock goes up for sale makea million dollars profit. Hire a lobbyist. Bribe the governor to putquestions about barometers on high school regents exams. Then create acontest to see who can find the height of a building using a barometer.The winner gets a million bucks. Of course no one really wins, but you getthe answer for free. Or you could conduct a market survey to measure thedemand for barometers, and use this to measure the approximate heightsubject to market fluctuations.

98: PhysicistGet some poor forlorn overworked repressed suffering graduate student tosolve this problem for you.If he gets the wrong answer threaten to fire him. Of course you alreadyknow the answer.This was just for fun.Then ask your undergraduates the question on an exam. Somehow none of themget the right answer.Initiate a program to measure the height of the building from outer spacesomehow mysteriously using the barometer. Send the experiment on aspace-shuttle research mission. Put it on your web-site and resume.

99: EngineerIt is perfectly obvious. Measure the height of the barometer. Get asurveying telescope. Form a triangle such that the top of the building andthe top of the barometer line up as seen in the telescope. Then measurethe distances along the base of the triangle and compute the ratio. (Ofcourse this doesn't work but then ....... back to the drawing board).

100: AnthropologistMove to a prehistoric jungle society of pygmies who live in grass huts.They are so short that you can measure the height of thier "scyscraper"directly. Barometers did not exist in prehistoric times.


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101: PsychiatristThinks to himself: This patient is extremely frustrated. I will chargehim extra.Says to patient: How long have you been having this recurring fantasy

about the barometer. I believe you are obsessed with it.

102: AnarchistDye your hair blue and throw the barometer at the building.how the fuck can an anarchist measure anything?

103: DoctorDoctors use manometers all the time.Find a patient with fear of heights. Use the barometer to measure the

patient's blood pressure at the bottom of the building. Stick his head outof the window at the top of the building and measure his blood pressureagain. Compute the height from the ratio of blood pressures.104: Dry methoda) buy a lot of dry sand (e.g. the whole Southern Lybia, oil wells excluded)b) use the barometer as a shovelc) cover the building with a perfect cone of sand, avoiding windy daysd) measure the area covered by the sand, obtaining diameter of the cone basee) knowing the natural slope of the sand you can easily obtain the heightof the building

105: Wet method (requires a lot of barometers of many types)a) use the barometer as a shovelb) dig a big hole (bigger than the bulding)c) use a barometer (better the type mounted on a wood tablet) as a troweland cover hole walls with concrete until you have a waterproof basind) buy as many water barometers as you cane) remove water from water barometers and put it into the basinf) seal all doors and windows of the building with duct tapeg) carefully put the building into the basinh) measure the volume of water moved by the building

106: Amazon (not the bookshop!) methoda) remove the glass pipe from a barometer and open both endsb) tie a light rope to the tail of an arrowc) put the arrow into the glass piped) go on the top of buildinge) blow the arrow into the nearest tree

f) measure the ropeg) solve the triangle formed by the rope and the building

106b) Another Amazon method - don't require rope but a stopwatcha) remove the glass pipe from a barometer and open both endsb) put an arrow into the glass pipec) hit a pedestriand) start the stopwatche) stop the stopwatch when you hear the howl

f) multiply time x sound speed


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This must be repeated many times because reaction time of subjects may vary.In any case the last method has the advantage that you can verify yourresults in a easy way: if a M-16 bullet shooted by the police has x energywhen launched, and y energy when it hit you, you can (well, ballistic

experts can) know the distance between the gun and the hole in your head,thus measures can be compared.

107: Internet methoda) ask everybody on the Net to submit you a solutionb) print every message (remember to number the pages!)c) put the pile of paper aside the building until you reach the topd) use the barometer as paperweighte) multiply the number of pages for the thickness of the paper

108: Remove mercury from barometer. Place drop of mercury so it closes acircuit between two parallel non-mercury-wettable conductors at a knownpotential difference. Measure speed & direction of motion of droplet dueto JxB forces. Rotate setup about a vertical axis until maximum speed isfound. This gives the direction & magnitude of the vertical component ofthe local geomagnetic field.

Repeat at top of building.

Compare differences to know characteristics of the geomagnetic field.This will give height of building.109 :Well, if one drilled a small hole in a the bottom of the barometer,one could establish the rate at which the mercury drips out of thebarometer. Then one could attach a small electric motor to the top of thebuilding. It could raise the barometer at a known rate. Using the amountof missing mercury, one could calculate the time it took to raise thebarometer to the roof. Ergo, the height of the building is now known_

110. Drink the mercury. If there's an afterlife, ask God how tall the

building was. If there isn't an afterlife, who cares that you don't knowthe height of the building?

111. Set the barometer in the middle of the building. Don't look at it asits wave function expands. When its wave function encompasses the entirebuilding, solve Schroedinger's equations.

112. Find a flammable barometer. Burn it and measure the time it takes forthe smoke to reach the top of the building.

113. Give it to an MIT student and tell him to transform it into a roboticbarometer specially designed to measure the height of buildings.

114. Tie the barometer to a string. Swing it in front of the architect ofthe building while muttering, "You are getting very sleepy. When I snap myfingers, you will tell me the height of the building."


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115. Find a spot on the ground with a known value for hardness. From thetop of the building, throw the barometer down to this spot. (You could alsothrow from the ground, but you would have to throw harder.) Repeat untilthe barometer bounces up to the top of the building. Measure the force of

your throw and calculate the height of the building.

116. Find a barometer the size of the building. Measure the barometer.

117. Weld barometers to the top of the building until they reach themoon. The building is approximately a quarter of a million miles tall.

118. Take the current air pressure and divide by zero. Your barometer (andyour test paper) will burst into flames to prevent a violation of

mathematical law. As the professor finds another copy of the test to giveyou, sneak into his desk and find the answer key.

119. Heisenberg's Principle of Aesthetics: Measure the color of thebuilding so precisely that you cannot measure its size. With that done, anyguess is as good as the real answer.

120. Set the building on the barometer. Knowing the density, length, andwidth of the building as well as Young's Modulus for the barometer,calculate the height.

121. Take the volume of the building and divide by its width andlength. When you're done, hold the barometer in the air to signal to theprofessor that you are finished with your test.

122. Create your own system of measurement. The unit of length will be the"building." The building in question is precisely one building tall. Whenasked what the barometer was used for, state that it was around for moralsupport.

123. Hold the barometer between the index finger and thumb on your lefthand. Hop twice on each foot before breaking out into disco. This is therain dance for a certain Native American tribe. When the rain falls, choosea drop and measure its velocity at the top of the building and its velocitywhen it reaches the bottom of the building. Subtract the former value fromthe latter, then apply this into the gravity/acceleration formula.

124. Set a tape measure at the bottom of the building. Tie a rope to one

end, string it (the rope) up around a pulley on the top of the building. Atthe other end of the rope, affix the barometer as a counterweight. Let itloose as the weight of the barometer pulls the tape measure to the top ofthe building. Go to the bottom and read the tape measure.

125. Set a laser at the top of the building. Fire the laser to the groundand have it reflect off the barometer. Then, suddenly rotate the barometersuch that the laser is firing at the building. When the building vaporizes,its height should be zero. You may wish to set the laser on the ground,

though, so you can use it again when you measure the next building.


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126. Briskly rub the barometer with a silk handkerchief. Hammer an ironspike into the ground at the base of the building. Hold the barometerdirectly over the spike for one minute, recording any electric

sparks. Repeat many times, and then use the probability of an electric arcto calculate the distance between the barometer and the grounding wire,which is also the height of the building.

127. (Works only for underwater buildings). Find a barometer that uses aliquid lighter than water. Hold it at the base of the building and letgo. Time it as it floats past the top of the building. Calculate theheight.

128. (Only works for buildings in environments with negligible air andgravity, i.e. space). Move the barometer at a steady speed along the heightof the building while timing it. As every good student knows, d=rt.

129. Use the barometer to measure the density of a pool of liquid. Weighthe building and drop it into the liquid. Time the building as it sinksinto the liquid. Calculate the height.

130. Hit the barometer onto a piece of flint. Start a small fire. When thefire alarms ring, the building is evacuated. Extinguish the fire, pull outa tape measure, and measure the building without anybody standing around tosee that you didn't really use the barometer.

131. Give the barometer to your younger sibling, who will run outside toplay with it. Now that you have peace and quiet, do some internet researchto find the height of the building.

132. (Omega must be greater than one and the cosmological constant must beless than one for this next suggestion to work) Allow the barometer to comeinto contact with an anti-barometer. The explosion should rip the buildingoff its foundation and send it into deep space. Wait until the gravity ofthe universe causes it to collapse on itself. Since the cosmologicalconstant is less than one, the universe should curl in on itself. When theuniverse's diameter is small enough for the building's top and bottom tomeet, measure the universe's diameter and multiply by pi, assuming that thespace-time continuum is perfectly spherical.

133: Walk to a comfortable distance from the building. Place the barometer on the

ground and sit on it to rest your feet. Now count the number of stories in thebuilding and multiply it by about 3 meters (10 feet).

134: Take a barometer to the top of the building, attach a long rope to it, lowerthe barometer to the street and then mark the point where it is. Bring it up anddrop it. Due to the Coriolis force, the barometer will not fall in the same point asbefore, but in another one, in westward direction. The distance between these twopoints is univocally determined by the height of the building (and vice versa).That's it!


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135: Here's another way: Tie a string to the barometer. Take the barometer tothe four corners of the building's roof, and use it as a plumb bob. Use thedifference in angles at the corners to find the distance from the roof to thecenter of the Earth, based on the Earth's curvature. Subtract the known radius of

the Earth to get the building's height.

136:Instruments: A barometer, an anemometer, a a lead mass >=40kg(pointed) anda stop watch, a set of flaps

Just drop this lead mass and mark where this falls. Draw a circle ofinfinite radius around this spot. Get a lab-view program and do real timedata acquisition of wind-speed readings from top and bottom of thisbuilding. Drop the Barometer with the set of flaps attached to it to inducedrag and when this barometer falls just measure the deviation form the thespot. If you tun into problems, remember your lab-view program? Aresolution of a least 0.05mS is fine then you can compute temporally howmuch the wind contributes to the deviation. This does not solve the problemdoes it? We are just getting warmed up. Remember statistical mechanics? Youwill need it now... you will need to standardize the deviation from a knowndistance call this quantity x and then we can sum x as a unit of measure ofthe building height or alternatively you can measure this with actual

numbers!

137:

1) Bring the barometer in such a linear motion, that it passes thebuilding both at ground level and at it's uppermost level.2) Be sure not to know anything about the speed of the barometer at groundlevel, you know it's exact location now.3) Be sure not to know anything about the speed of the barometer at it's

uppermost level, you now know the exact location of this level as well.4) The height of the building is given by Height = 3) - 2)

138:Postulate 1) Assume the building is spherical.Postulate 2) Assume the building is in a vacuumPostulate 3) Assume \hbar = 1Postulate 4) Assume the height of the building is 100 meters.

**The height of the building is 100 meters**

proof:1) Write the height H as H = 0.5H + 0.5H2) According to postulate 4 the height of the building is 100 meters ->0.5H = 50 meters3) Combining 1) and 2) we get: H = 50 + 50 = 100, so the height of thebuilding is 100 metersQ.E.D.

139:Put a glass cap at the open end of the barometer and turn it over so


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that it acts like a mirror. Place the barometer facing down from theroom. Now with a laser pointer direct the beam at an angle from theground and see where you get the light dot reflected from thebarometer. You know the angle and know the horizontal distance between

two dots. Its simple trigonometry after this.

Of course, you could use the barometer to measure the pressure at the top andthe bottom of the building and use the air density...

Physics Jokes 3

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Transcript of Physics Jokes 3