1. Physics Review

2. 1) Write Newton’s 1st Law. Give an example.
An object in motion stays in motion…
An object at rest remains at rest….
Unless acted upon by an unbalanced force!
For example, when you slam on the
breaks of a car, stuff flings forward
off the seat (because it was in motion
and remains so…)

3. 2) Write Newton’s 2nd Law. Give an example.
F = ma
It is easier to push a VW beetle than
a Chevrolet Suburban…
A bullet hurts more that is shot than
thrown at you!

4. 3) Write Newton’s 3rd Law. Give an example.
For every action there is an
equal and opposite reaction
examples include:
a rocket shoots “stuff” down and goes up
Recoil: a bullet moves forward as
the gun pushes back into your shoulder

5. If force is held the same… when mass is increased, acceleration
4) Explain how force, mass, and
acceleration are related. Not just the formula.
F = ma
If force is held the same…
when mass is increased, acceleration
will decreased.
If mass is the same, it takes greater
force to obtain greater acceleration
If acceleration held the same, a larger
mass requires a larger force

6. running standing still walking
5) Draw a graph for the following scenarios:
A) A person running fast
B) A person walking
C) A person that is standing still
D) A person running that stops for a water break.
standing still
walking
running

7. 6) Explain the speed graph.
Who ran fastest?
Albert; he got to 100 meter first!
Slowest?
Charlie; he took the longest to get to 10 meters

8. Explain the speed graph.
Who stopped (and at what time)?
Charlie stopped from 8 to 13 seconds

9. 6) Explain the speed graph to the right.
C. How fast was Charlie going in
the first eight seconds?
S = d/t = 50m / 8 sec = 6.25 m/s

10. Explain the speed graph to the right.
D. Who made it to the 20m point first?
Charlie; he was there in about 3 seconds!
How far was the race?
100 meters

11. 7) Draw and label a picture of balanced forces.

12. 8) Draw and label a picture of unbalanced forces.
or even….
20N
20N

13. Time (t) = .5 hr (half an hour!) S=d/t = 15Km/.5hr = 30Km/hr
9) Spencer watches a storm cloud on a weather map.
The storm cell moved 15 Km in half an hour. What is
The storm’s speed in Km/hr?
S= d/t
Distance (d) = 15Km
Time (t) = .5 hr (half an hour!)
S=d/t = 15Km/.5hr = 30Km/hr
Answer: 30 Km/hr

14. S= d/t Distance (d) = 112Km Time (t) = 1.3 hr
10) Susan is driving her Lamborghini on I-45 heading north. She drove 112 Km to Huntsville in 1.3 hrs. What is Susan’s speed in Km/hr?
S= d/t
Distance (d) = 112Km
Time (t) = 1.3 hr
S=d/t = 112Km/1.3hr = 86.15Km/hr
Answer: Km/hr

15. S= d/t Distance (d) = 1m Time (t) = .26 s S=d/t = 1m/.26sec = 3.85m/s
For a science experiment, Aneeah rolls a metal
ball down a 1 meter ramp. The ball takes .26 seconds
To go down the ramp.
What is the ball’s speed in m/s?
S= d/t
Distance (d) = 1m
Time (t) = .26 s
S=d/t = 1m/.26sec = 3.85m/s
Answer: m/s

16. What causes an object to accelerate?
12) What is acceleration?
What causes an object to accelerate?
acceleration is a change in velocity.
It includes:
speeding up
slowing down
changing direction
acceleration is caused by
unbalanced forces

17. F = ma mass (m) = 4.4 Kg acceleration (a) = 1.8 m/s2
13) Antonio lifts a 4.4Kg weight over his head
with an acceleration of 1.8m/s2. How much force
is Antonio exerting on the weights?
F = ma
mass (m) = 4.4 Kg
acceleration (a) = 1.8 m/s2
F=ma = 4.4Kg x 1.8 m/s2 = 7.92 kg*m/s2
Answer = 7.92 N

18. F = ma mass (m) = 33 Kg acceleration (a) = 2.2 m/s2
14) Dylan pushes a 33Kg cart with school supplies
across the floor by accelerating it at a rate of 2.2m/s2.
How much force was applied to the cart.
F = ma
mass (m) = 33 Kg
acceleration (a) = 2.2 m/s2
F=ma = 33Kg x 2.2 m/s2 = 72.6 kg*m/s2
Answer = 72.6 N

19. F = ma mass (m) = 96 Kg acceleration (a) = 1.1 m/s2
15) David and Mr. Clary compete in a tug-of-war.
David pulls Mr. Clary (whose mass is 96Kg) with
an acceleration of 1.1m/s2.
What force is David applying?
F = ma
mass (m) = 96 Kg
acceleration (a) = 1.1 m/s2
F=ma = 96Kg x 1.1 m/s2 = kg*m/s2
Answer = N

20. F = ma Force (F) = 112 N acceleration (a) = 8 m/s2 F=ma
Grace applies a force of 112N to a wagon
The cart accelerates at 8 m/s2.
What is the mass of the cart?
F = ma
Force (F) = 112 N
acceleration (a) = 8 m/s2
F=ma
112N= m * 8 m/s2
Divide both sides by 8!
m= 34
Answer = 34 Kg

21. F = ma Force (F) = 51N mass (m) = 17 Kg F=ma 51N = 17Kg x a 3 m/s2
Caleb applies a force of 51N to a box. The box
Has a mass of 17Kg. What is the box’s acceration?
F = ma
Force (F) = 51N
mass (m) = 17 Kg
F=ma
51N = 17Kg x a
Divide both sides by 17
3 m/s2
Answer = 3 m/s2

22. for example: 68 miles per hour north
18) What is velocity?
Speed with direction
for example: 68 miles per hour north or
28 m/s down the ramp

23. 19) What is potential energy?
Stored energy. Energy that has the
ability to “do work.”
examples include
a rollercoaster at the top of a hill….
a battery (chemical potential energy)
the stress built up in a fault between
two of Earth’s plates.

24. 20) What is kinetic energy?
Energy of motion…..
Examples include:
an apple falling,
a rollercoaster at the bottom
of the first big hill,
a baseball flying through the air.