THE LANGUAGE

OF PHYSICS

ACCELERATION= aa= (vf-vi)/t

vf- final velocity, vi- initial velocity

UNITS ARE m/s2

CONSTANT a

NEGATIVEa

POSITIVEa

a

tCONSTANT

V

a

t

a

t

a

t

CHANGE SPEED OR DIRECTION

VELOCITY= v

v= d/t= units are m/s

CONSTANT a

NEGATIVEa

POSITIVEa

v

tCONSTANT

V

v

t

v

t

v

t

SPEED AND DIRECTION

DISTANCE- dHow far you have traveled

Measured in m, km, miles, cm

CONSTANT a

NEGATIVEa

POSITIVEa

d

tCONSTANT

V

d

t

d

t

d

t

DISPLACEMENT- distance from starting point.

d

tNot

Moving

SCIENTIFIC METHOD

PROBLEM-What is the question to be studied

HYPOTHESISIf ____ is the answer then

the data will show _______ because.

CONCLUSIONHow the data relates to the hypothesis, does the trend match or not.

DATACharts and graphs used to identify a trend in the data

PROCEDUREHow you will prove your point. Be aware of safety.

QUESTIONBased on the data what would be the next logical question to study.

CONTROLS- What would happen if nothing was changed

VARIABLES- Things that Could alter the results

INDEPENDENT- Changed by the scientist (x axis)

DEPENDENT- The result of the change, what is measured. X axis

TESTABLE- Must be

GOOD SCIENCEIS REPEATABLE

FREE FALLFalling object only being effected by

gravityvv= at

dv= vi + 1/2at2

AIR RESISTANCE- upward Force that reduces the effects of gravity in free fall

GRAVITY- down force created by the earth, causes acceleration in free fall

TERMINAL VELOCITY when air resistance has built up the ability to stop acceleration

g= 9.8 m/s2ACC caused by gravity ALWAYS

KINEMATIC EQUATIONSUse Equation containing known and one unknown

variable to find

What I have- variables given in problem

What I need the question is asking for this variable in this unit

Formula- How will I use the known to solve for the unknown

d= vit + ½ at2

d= (vi + vf)/ 2 t

vf2= vi

2 + 2advf= vi + at

RELATIVE MOTION• Motion based on the position (REFERENCE FRAME) of the observer.

SEES CAR AT 60 km/h and grandpa is

moving very slow

SEES CAR AT 49 km/h and runner at

11 km/h

SEES RUNNER AT 60 km/hr and grampa at

49 km/hr

PROJECTILE MOTION• Horizontal Speed is Constant• Vertical Speed changes due to gravity• 45 degree angle is most efficient• 2 angles that equal 90 degrees produce

the same landing point• Launch angle is separated into vertical

and horizontal components

Vi =VfVi =Vf

vx= v*cos° (horizontal speed)vy= v*sin ° (vertical speed)dy (height)= ½*9.8*t2

dv (distance)= v*t

LAW OF INERTIA• Newton’s First Law of Motion

• Inertia- the ability of an object to not be changed by force.• An object will remain at rest or in motion unless a force

(greater than its inertia) acts upon it.

Weight in Newton's (inertia)= Kilograms X 9.8 m/s2

22kg x 9.8 m/s2 = 215 N (inertia)

Conversions

10lbs x 2.2= 22Kg

LAW OF ACCELERATION• 2nd Law of Motion• Once inertia is overcome the change in an object will be

proportional to the force applied to it• Motion occurs or changes when forces on an object become

unbalanced.

Force (N)= mass (Kg) x Acceleration (m/s2)

LAW OF ACTION REACTION• Newton's 3rd law of motion.

• For every action force there is an EQUAL AND OPPOSITE reaction force.

• Example when two cars hit the force they experience is the same, but the car with less inertia tends to take more

damage and bounce off farther.

WORK AND POWER• Work is the application of force which causes movement, if

there is no movement there is no work.• Power how quickly work can be done.

If mass is = than taller

Did more work.

If work is equal than faster has more power.

ANGULAR MOTION

Theta is the symbol for angular distance, similar to meter for linear distance. It is the arc length/radius. The unit for distance is a radian

The term alpha means angular acceleration The units are rads/s2 similar to m/s2 in linear acceleration.

The term omega means angular speed. The units are rads/s similair to m/s in linear speed..

t t

if

Satellites stay in orbit using angular speed to fight the pull of gravity, the lower the orbit the faster the speed to stay balanced

WORK AND POWERThe ability to move an object using force divided

by the time it takes to get it done.

MOMENTUMForce created by the size and speed of the

object. Force you hit with.

Momentum is conserved meaning the total momentum in a collision does not change, the amount in each object does

ENERGY

KE= 1/2mv2

CONSERVATION OF ENERGY means that the total energy in a closed system does not change, PE + KE always remains constant. MAX PE = MAX KE

Potential- position, Kinetic- motion

Unit= Joules