PHYSICS REVIEW SHEET
UNITS: There are 7 fundamental units
1kg  1000 g  1g  1/1000kg
Mass: kg, g
Length: km, m, mile 1km  1000m  1m  1/1000km
1hr  3600s
Time: hr, s
Converting Units
1
km 10 00 m 10


m/ s
hr 36 00 s 36
ex. 90km / h  90 
10
m / s  25m / s
36
Scientific Notation – decimal comes after the first digit
a.bc  10 x
ex.
0.000000789  7.89  107
ex.
950000000  9.50  108
Graphing Data: slope 
rise y

run x
Slope of a distance-time graph gives the velocity (speed).
Slope of a velocity-time graph gives the acceleration.
An example of a linear relationship: straight line
Scalar & Vector Quantities
What is a scalar: magnitude only.
Ex: mass, speed, distance, time
What is a vector: both magnitude & direction.
Ex: velocity, acceleration, force
Kinematics
Constant motion: velocity remains constant; acceleration is zero v 
Accelerated motion: velocity changes (3 equations of motion)
a
v f  vi
t
 v f  vi  at ;
1
d  vi t  at 2 ;
2
d
t
km/h; m/s
a: m/s2
v f 2  vi 2  2ad
Newton’s 3 Laws: Law of Inertia; Law of Acceleration; Law of Force Pairs F  ma
Weight is a force w  m  g
Unit: N  kg  m / s 2
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Projectiles & Trajectories
Free fall motion: a  g  9.80m / s 2
Projectile motion: combination of vertical & horizontal motions simultaneously
Note: Time to fall vertically down is same as time traveled horizontally.
Vertical motion: acceleration up is negative; acceleration down is positive and both are
equal to 9.80 m/s2
Horizontal motion: no acceleration in the horizontal direction; motion is constant
Newton’s 3 Laws of Motion
Newton’s 1st law is the law or inertia: object at rest or in uniform motion continues in its
state of rest or uniform motion.
Inertia is the ability to resist changes in motion. Mass is a measure of inertia.
Newton’s 2nd law is the force law. The acceleration of an object is proportional to the
force acting on the object and inversely proportional to its mass. F  m  a (Newton: N)
The weight of an object is the force due to gravity. w  m  g
Newton’s 3rd law is the law of force pairs; to every action, there is an equal and opposite
reaction
Momentum
Momentum is the product between an object’s mass and its velocity p  m  v
(kg  m / s )
Impulse is equal to the change in momentum or average force times contact time: J  p  F  t
Conservation of momentum: Momentum conserved in any collision.
Total Momentum before = total momentum after
m1v2  m2 v2  m1v3  m2 v4
Elastic collisions:
m1v2  m2 v2  (m1  m2 )v3
Inelastic collision:
Uniform Circular Motion
Centripetal Acceleration & Centripetal Force are both directed towards the center of
circle. ac 
v2
r
Fc  m
v2
r
Velocity is always tangential to the radius.
Time to go around once is called the period, T
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Newton’s Universal Law of Gravitation
Gravitational force is proportional to product of masses FG  m1  m2
Gravitational force is inversely proportional to square of distance FG 
1
d2
As d increases, FG decreases: ex. d doubles FG decreases by four
Work
Work is the product between force and distance moved W  F  d
Maximum work is done when the applied force is parallel to the distance moved.
No work is done when the applied force is perpendicular to the distance moved

The unit of work is the joule (J) 1J  1kg  m 2 / s 2

Energy
Energy is the ability to do work. W  E . The unit of energy is the joule (J).
Power
W
 F v
t
Power is proportional to the work done and inversely proportional to the time
Power is the rate at which work is done. P 

The unit of power is the Watt (W). 1W  1J / s  1kg  m 2 / s 3

Potential Energy
Energy of an object by virtue of its position above the Earth. PE  mgh
Potential energy depends on the objects mass, height and acceleration due to gravity.
Work done is equal to negative change in potential energy. W  PE
Kinetic Energy
1
Energy of an object by virtue of its velocity (speed). KE  m  v 2
2
Kinetic energy is proportional to the object’s mass and the square of its speed.
Work done is equal to change in potential energy. W  KE
Conservation of Mechanical Energy
Mechanical energy is the sum of the potential energy and kinetic energy E  KE  PE
Energy is neither created nor destroyed; but it is transformed from one form to another.
Lost in PE = Gain in KE, vice versa.
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TEST YOURSELF…WHAT DID YOU UNDERSTAND?
1. SCIENTIFIC & DECIMAL NOTATION
a. How do you write a decimal in scientific notation and vice versa?
b. What is the form?
2. METRIC PREFIXES
a. What are the metric prefixes?
b. What values do the symbols represent?
3. MOTION
a. What is motion?
b. How do you measure motion?
4. SCALARS & VECTORS
a. What is a Scalar?
b. What is a Vector?
c. Give some examples of both scalar and vector quantities.
5. VELOCITY
a. What is Velocity?
b. What is the formulas for Velocity?
c. What is the Unit?
d. Is it a Scalar or Vector?
6. MOMENTUM
a. What is momentum?
b. What is the formula for momentum?
c. What is the unit of momentum?
d. What is impulse?
e. How is impulse and momentum related?
f. How does the force changes with time in a collision?
7. ACCELERATION
a. What is Acceleration?
b. What is the formula for acceleration?
c. What is the unit for acceleration?
d. How do you know an object accelerated or decelerated?
e. What is the acceleration of a projectile?
f. What is the acceleration of an object when its thrown straight up into the air?
8. FORCE
a. What is Force?
b. What is the formula for force?
c. What does a force do?
d. What is the unit of force?
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9. WEIGHT
a. What is Weight?
b. What is the formula for weight?
c. What is the unit of weight?
d. Is weight a force?
e. Is your weight the same everywhere you go in the universe?
10. MASS
a. What is Mass?
b. What is the unit for mass?
c. Is your mass the same everywhere you go in the universe?
d. How is mass & INERTIA related?
11. UNIFORM CIRCULAR MOTION
a. What is the direction of the velocity of an object moving in a circle?
b. What is the direction of the acceleration of an object moving in circular motion?
c. What is the direction of the force of an object moving in circular motion?
d. What happens to the force as the velocity increases/decreases?
e. What happens to the force as the radius increases/decreases?
f. What are the names of the force and the acceleration?
12. MOMENTUM
a. What is momentum?
b. What is the unit of momentum?
c. What is impulse?
d. How is impulse and momentum related?
e. How is impulse and force related?
f. What is conservation of momentum?
g. What is an elastic collision?
h. What is an inelastic collision?
13. UNIVERSAL GRAVITAION
a. What is Newton’s law of universal gravitation?
b. How does the force as the masses change?
c. How does the force change as the distance between the masses change?
14. WORK
a. What is Work?
b. What is the formula for work?
c. What is the unit of work? What is the base unit of work?
d. When is work done?
15. ENERGY
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a. What is energy?
b. What is the unit of energy?
16. POWER
a. What is power?
b. What is the formula of power?
c. What is the unit of power? What are its base units?
d. What is a horsepower (hp)?
e. What does power depends on?
17. POTENTIAL ENERGY
a. What is the potential energy of an object?
b. What variables do the P.E. depends on?
c. What is the unit of P.E..?
d. How does the P.E. changes with respect to its variables?
e. How is P.E. and work related?
18. KINETIC ENERGY
a. What is the kinetic energy of an object?
b. What variables do the K.E. depends on?
c. What is the unit of K.E..?
d. How does the K.E. changes with respect to its variables?
e. How is K.E. and work related?
19. CONSERVATION OF MECHANICAL ENERGY
a. What is the law of conservation of energy?
b. What is mechanical energy?
c. Is all the energy in the universe constant?
d. What does it mean for energy to be “lost”?
e. What happens to an object, in terms of its energy, as it falls freely to the ground?
f. What happens to an object, in terms of its energy, as it projected upwards?
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