PHYSICS LECTURE RESOURCES

Introduction to Physics and 1-D Motion

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Happy Model Hr. Sec. SchoolUdhampur, India

Email: mineesh.gulati@gmail.com

Prof. Mineesh Gulati

Text Book

Phundamentals of Physics F

7th Edition

Halliday, Resnick and WalkerHalliday, Resnick and Walker

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Confucius say …Confucius say …

I hear…

…….I forget

I see…

……I remember

I do…

……I understand

I hear…

…….I forget

I see…

……I remember

I do…

……I understand

lectures

slides

problems

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PtolemyPtolemy

KeplerKepler

Kelper and Tycho-BraheKelper and Tycho-Brahe

NewtonNewton

??????????

Marie CurieMarie Curie

Maria MayerMaria Mayer

YukawaYukawa

GalileoGalileo

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Earth WaterAirFire

Earth WaterAirFire

In 500 BC Physics was quite simple

KinematicsKinematics AstronomyAstronomyDynamicsDynamics

Objects stay at rest unless being pushed!

Objects stay at rest unless being pushed!

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Aristotle384 BC -322 BC

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(1971)

The retrograde motion in the orbit of mars was a serious challenge to the standard geocentric cosmology which demanded that all the planets orbit the earth. Ptolemy (85-165 AD) came up with an elaborate mechanism to keep the earth at the center of the Universe.

The retrograde motion in the orbit of mars was a serious challenge to the standard geocentric cosmology which demanded that all the planets orbit the earth. Ptolemy (85-165 AD) came up with an elaborate mechanism to keep the earth at the center of the Universe.

September 4

July 26

June 6October 14

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Ptolemy’s Epicycles (85-165 AD)

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Crystal sphere with starsCrystal sphere with stars

ParadiseParadise

EarthEarth

Can you imagine no change to this theory for more than 1000 years!

Can you imagine no change to this theory for more than 1000 years!

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Copernicus ~1540

Earth revolves around the Sun ---365 days

Earth rotates on its axis -- 1 day

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Retrograde motion according to Copernicus

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Galilei Galileo 1564 - 1642happyphysics.com

Kepler’s Laws of Planetary Motion

Johannes Kepler 1571-1630

Law 1 The planets circulate in eliptical orbits with the sun at one focus

Law 1 The planets circulate in eliptical orbits with the sun at one focus

Law 2 A line joining the planet to the Sun sweeps out equal areas per unit time.

Law 2 A line joining the planet to the Sun sweeps out equal areas per unit time.

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The law of areas

When closer to the sun, the planet moves faster

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A CHRONOLOGY OF THE SCIENTIFIC REVOLUTION 

1440 Gutenberg completed his wooden press which used metal moving type.

1543 Nicolas Copernicus publishes On The Revolutions of the Heavenly Spheres

1571 Tycho Brahe develops instruments for precise astronomical observation and records positions of stars and planets. He creates a Tychonic System of the cosmos called geoheliocentric. Planets revolve around the sun, while the sun and planets still revolve around the central earth 

1609 Johannes Kepler publishes his first and second Laws of Planetary motion. (l) Planetary orbits are elliptical.

(2) Planets sweep out equal areas in equal times 

1609 Galileo Galilei develops a telescope of 30X magnification and begins observations 

1619 Kepler announces his Third Law of Planetary Motion which stated that a planet's distance from the sun is related to the time it takes a planet to revolve around the sun

1632 Galileo publishes his Dialogues on the Two Chief Systems of the World which popularized the Copernican system and articulated the concept of a world subject to mathematical laws 

1633 Galileo is denounced by the Inquisition and forced to recant his belief in Copernican theory 

1667 Sir Isaac Newton constructs the first reflecting telescope

1687 Newton publishes his Principia Mathematica which explained gravitation, contained the components of Newtonian Physics (matter, motion, space, attraction), and challenged the Aristotelian/Ptolemaic cosmos. 

A CHRONOLOGY OF THE SCIENTIFIC REVOLUTION 

1440 Gutenberg completed his wooden press which used metal moving type.

1543 Nicolas Copernicus publishes On The Revolutions of the Heavenly Spheres

1571 Tycho Brahe develops instruments for precise astronomical observation and records positions of stars and planets. He creates a Tychonic System of the cosmos called geoheliocentric. Planets revolve around the sun, while the sun and planets still revolve around the central earth 

1609 Johannes Kepler publishes his first and second Laws of Planetary motion. (l) Planetary orbits are elliptical.

(2) Planets sweep out equal areas in equal times 

1609 Galileo Galilei develops a telescope of 30X magnification and begins observations 

1619 Kepler announces his Third Law of Planetary Motion which stated that a planet's distance from the sun is related to the time it takes a planet to revolve around the sun

1632 Galileo publishes his Dialogues on the Two Chief Systems of the World which popularized the Copernican system and articulated the concept of a world subject to mathematical laws 

1633 Galileo is denounced by the Inquisition and forced to recant his belief in Copernican theory 

1667 Sir Isaac Newton constructs the first reflecting telescope

1687 Newton publishes his Principia Mathematica which explained gravitation, contained the components of Newtonian Physics (matter, motion, space, attraction), and challenged the Aristotelian/Ptolemaic cosmos. 

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JOHANNES VERMEER

~1660

The year Newton postulated gravity!

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The Astronomer

Vermeer 1668

The Geographer

Vermeer 1668/9

These paintings reflect the blossoming of scientific enquiry in seventeenth century Europe.

At this time, Newton is making the first reflecting telescopes,

Louis XIV is building an observatory in Paris,

the satellites of Jupiter are being used for navigation at sea, and

Huygens has discovered the sixth satellite of Saturn.

The old views, that it would be presumptive for man to probe too closely the sky or the Earth, are being replaced by modern principles of science.

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Woman peeling potatoes Gabriel Metsu (~1660)

Courtyard (1658)

Pieter de Hooch

Milkmaid Vermeer (~1660)

Sick ChildSick Child Gabriel Metsu (1660)

At this time artists began to paint pictures of everyday people and events.

Women and their children

The everyday tasks of caring for a family

The caring love for a sick child

At this time artists began to paint pictures of everyday people and events.

Women and their children

The everyday tasks of caring for a family

The caring love for a sick child

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Monteverdi

Bach

Vivaldi

Scarlatti

Purcell

Mozart

Handel

And over this same period, as Physics became liberated and questioning, as architecture flourished, and art became less constrained and reflected the real world, there developed a blossoming of music.

The baroque period: new enlightened and liberated forms of music, and newly developed instruments.

The chamber works of Vivaldi

The splendor of Bach’s organ works

The choral works of Monteverdi and Handel

The new opera works of Purcell

The genius of Mozart

So we see that in this revolutionary time, Physics was ready for Newton (born in1643), to revolutionize our understanding of mechanics..

And over this same period, as Physics became liberated and questioning, as architecture flourished, and art became less constrained and reflected the real world, there developed a blossoming of music.

The baroque period: new enlightened and liberated forms of music, and newly developed instruments.

The chamber works of Vivaldi

The splendor of Bach’s organ works

The choral works of Monteverdi and Handel

The new opera works of Purcell

The genius of Mozart

So we see that in this revolutionary time, Physics was ready for Newton (born in1643), to revolutionize our understanding of mechanics..

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Isaac Newton

1642-1727happyphysics.com

Why is it so!!!

Riding a bikeRiding a bike

The unstable topThe unstable top

Racing down hillRacing down hill

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For you to read by next lecture

Review of Year 12 Physics2.3 Defining position in 1D2.4-2.6 Definitions of average and instantaneous

speed and acceleration in 1D. The relationships between these

2.7 The case of constant acceleration (VCE Physics)

Read this for next lecture3.2- 3.6 Specifying vectors

Sections from the Text book:

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For Next Lecture:What is her average speed?What is her average velocity? What do you mean by velocity?

To think about:

1 k

m 2 km

If she rode directly to school, what would be her speed? Velocity?

I will quiz you on this next lecture.I will quiz you on this next lecture.

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Here endeth

the lessonlecture

No. 1

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Rectilinear Motion

StraightStraight lineline MotionMotionKinematicsKinematics

HOW things moveHOW things moveDynamicsDynamics

Erect = straight

WHY things moveWHY things movehappyphysics.com

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xDistance travelled in equal time intervals

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x

Time (t)

Dist (x)

x

x

x

x

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Time (t)

Dist (x)

x

x1

t1

x2

x3

x4

x5

t2 t3 t4 t5

t

x

tt

xxavv

34

34

Dx

Dt

Average speedspeed = distance .

time taken

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Gradient of the x-t curve

Time (t)

Dist (x)

x

x1

x2

x3

x5

x6

t3

x4

t4

Dx

Dt

x4

t4

Dx

Dt

tx)t(v

0t

limit

dt)t(dx

)t(v

Instantaneous speed

t

x

tt

xxavv

34

34

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dt)t(dx

)t(v

If we know x(t), we can find v(t)

Position (x)

Position as a function of time

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dt)t(dx

)t(v

If we know x (t), we can find v(t)

time

time

time

Speed as a function of time

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dt)t(dx

)t(v

If we know x (t), we can find v(t)

dt)t(dv

)t(a

Similarly if we know v(t), we can find a(t) since

time

time

time

Acceleration as a function of time

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If we know a(t), we can find v(t), since:

dttatvfinalt

initt

.)()(

And from v(t) we can find x(t), since

finalt

inittdttvtx )()(

From acceleration speed distance

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If acceleration is constant, life is easy!

VCE easy

t0 t (t)

(acc

el)

(t)

spee

d

v0

atvv 0

Similarly

x-x0= v0t + ½ at2

v2 = v02 + 2as etc.

o

o

tt

vva

t

vva o

if t0 = 0,

See slide lect 2

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1-D (linear kinematics)

with constant acceleration

1-D (linear kinematics)

with constant accelerationVCE Physics

See modified slide lecture 2

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2-D Kinematics

have magnitude and direction

distance displacement

speed velocityhappyphysics.com

Distance from Melbourne to Bendigo = 1600 km

Displacement of Bendigo rel. to Melbourne = 200 km (NW)

Average velocity = displacement/time = 200/2 = 100 km/h N.W.

Average speed= distance/time = 1600/20 = 80 km/h

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Y

X

P1 (x1, y1)

P2 (x2, y2)

y1

y2

x1 x2

r1

r2

12

r1 = ix1 + jy1 +( kz1)r2 = ix2 + jy2 +( kz1)

r

r = i(x2- x1) + j(y2-y1) +r = i x + j y +

y

x

r = r2 - r1

r = (ix2 + jy2) -(ix1 + jy1)

r1 is the vector displacement of P1rel to originr2 is the displacement vector of P2 rel to origin r is the displacement vector of P2 rel to P1

The length of r1= 21

21 yx

Unit vectors

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P1 (x1, y1)

P2 (x2, y2)

12

r

Y

X

y1

y2

x1 x2

r1

r2

y

x

t

rvav

dt

rd)t(v

t

r

0)t(v

t

limit

Average velocity

Vav is in direction of Dr

Instantaneous

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