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Physics
Newton’s Law Quiz Study Guide
Friday, November 18th
Format
1) 25 Multiple Choice
2) 15 Identify Law
3) 5 Short Answer
Content
1) Newton’s Laws
2) Problem Solving
a. Newton’s 1st Law
b. Newton’s 2nd Law
c. Newton’s 3rd Law
d. Static Friction
e. Kinetic Friction
Study Material
1)
2)
3)
4)
Notes
Problem Solving Practice
Study Guide
Labs/Worksheets
Study Questions – Multiple Choice
1) What is Newton’s 1st Law and give three specific examples.
2) What is Newton’s 2nd Law and give three specific examples.
3) What is Newton’s 3rd Law and give three specific examples.
4) Describe the difference between static and kinetic friction?
5) What is mass? How is it different than weight in definition and units?
6) How are mass, inertia, and force related to one another?
7) Which law explains the relationship between mass, inertia and force?
8) Define inertia.
9) How does Newton’s 1st Law of Motion apply to hauling logs at a timber factory?
10) What does Newton’s 2nd Law tell us about the relationship between the mass of an object
and its acceleration? What about force and acceleration?
11) If we double the mass of an object in motion, what would happen to its acceleration?
12) If we apply three times the force to an object as the original force applied, what would
happen to the object’s acceleration?
13) What causes objects to accelerate?
14) What two reasons are there for an object not moving when a force is applied?
15) What impact does friction have on the net force (total force) on an object?
16) What is a “force”?
17) A bug hits a windshield. Describe the forces experience by each.
18) Why doesn’t the person a gunfighter shoots go flying backwards? Explain in terms of
Newton’s 3rd Law.
19) What has more force exerted on it in free fall, a bowling ball or a ping pong ball?
Explain your answer in terms of Newton’s 2nd Law.
20) If an elephant were chasing you, its enormous mass would be very threatening. But if
you zigzagged while running, the elephants mass would be advantageous to you getting
away. Explain why in Newton’s 1st Law.
Short Answer/Problem Solving
21) If an object is pushed with a force of 45N, but the net force is 15N, what do we know
about the frictional force? Why?
Givens
Formula
Calculations
22) What force would you need to keep an object in constant motion (at a constant velocity)
if the frictional force is 20N?
Givens
Formula
Calculations
23) What force would you need to apply if you want to accelerate an object from rest if the
frictional force was 5N?
Givens
Formula
Calculations
24) What is the force needed to accelerate a 28N object at a rate of 4m/s2?
Givens
Formula
Calculations
25) What is the mass of an object that accelerates at a rate of 34m/s2 when a force of 12N is
applied?
Givens
Formula
Calculations
26) What is the acceleration of a 76kg object that moves due to a 180N force?
Givens
Formula
Calculations
27) What is the mass of an object that has a 27N weight?
Givens
Formula
Calculations
28) A sled with a mass of 50 kg is pulled along a flat, snow covered ground. The static
coefficient value of friction is .30 and the kinetic friction coefficient is .10.
a) What is the Force of Normal for the sled?
b) What force will be needed to start moving the sled?
c) What force is needed to keep the sled moving?
29) A boy exerts a 36 Newton force as he pulls a sled with a force of 52 N. What is the
coefficient value of kinetic friction between the rusty, metal sled runners and the partially
snow covered sidewalk?
Givens
Formula
Calculations
30) What is a Newton? Is it a measure of force or mass?
30) Explain what “reaction” and “action” forces are. Give an example of each.
31) If a sumo wrestler that weighs 378lbs. slams into another sumo wrestler that has a weight
of 343 lbs., explain the action and reaction forces of both wrestlers. Why would the
wrestlers not accelerate at the same rate upon impact?
Behavior
32) A jet engine pushes air backwards as the plane moves forward down a
runway.
33) A meteor in deep space (not planets or stars around) flies in a straight
path.
34) A very heavy mousetrap vehicle may not move.
35) Two football players try to push a car out of the ditch, but it does not
move.
36) A skateboarder drags her foot on the ground to slow down.
37) A driver pushes on the gas pedal and the car goes faster.
38) A boy wobbles backwards as he catches a dodgeball thrown at him.
39) You punch a wall and it hurts!
40) A sky diver increases her speed the longer she falls.
41) You’re in equilibrium while sitting in your chair.
42) It takes longer to slow a motorhome to a stop than a small family car.
43) A dump truck moves faster after it has dumped its load of gravel.
44) Bicycle racers bend over the handle bars to become as small as
possible during the race.
45) A Christmas ornament hangs from a tree branch, pulling the branch
down.
46) Christmas presents sitting under a Christmas tree stay there until
someone picks them up on Christmas morning.
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Study Questions Key
1) What is Newton’s 1st Law and give three specific examples.
An object at rest will stay at rest, an object in motion will stay in the same motion, until an
outside force acts on it.
A car sits in a parking lot and doesn’t move
A baseball flies straight through the air (force acting on it brings it down to the earth)
A chair sits in the classroom until someone moves it
2) What is Newton’s 2nd Law and give three specific examples.
Acceleration is inversely proportional to the mass.
Acceleration is directly proportional to the force.
An empty semi has more acceleration then a full semi because it has less mass
A football player can create more acceleration when pushing a child on a sled than most
cross country runners (football player can push with more force)
An object with more friction will slow faster, more force causes more deceleration.
3) What is Newton’s 3rd Law and give three specific examples.
Every action has an equal and opposite reaction
You sit and a chair and push down on the chair, the chair pushes up on you
You pull down on a pull-up bar, the bar pulls up on you
A bird flaps its wings, pushing down on the air, and the air pushes up on the wings
4) Describe the difference between static and kinetic friction?
Static is starting to move from a stop, kinetic is once the object is in motion
5) What is mass? How is it different than weight in definition and units?
Mass is the amount of matter, measured in grams(kilograms)
Weight is the force of gravity, as a force the unit would be newtons
6) How are mass, inertia, and force related to one another?
Inertia is the resistance to change in motion. The more mass something has, the more
inertia it has. The more mass or inertia it has, the more force needed
7) Which law explains the relationship between mass, inertia and force?
Newton’s 1st law is the law of inertia
8) Define inertia.
Resistance to change (in motion)
9) How does Newton’s 1st Law of Motion apply to hauling logs at a timber factory?
Big logs – lots of inertia, need lots of force to change the motion (start or stop its motion)
10) What does Newton’s 2nd Law tell us about the relationship between the mass of an object
and its acceleration? What about force and acceleration?
Increasing mass decreases acceleration = inversely proportional
Increasing force increases acceleration = directly proportional
11) If we double the mass of an object in motion, what would happen to its acceleration?
Doubling the mass will divide the acceleration by two
12) If we apply three times the force to an object as the original force applied, what would
happen to the object’s acceleration?
Multiplying the force by 3 will multiply the acceleration by 3
13) What causes objects to accelerate?
There must be an unbalanced force to create acceleration
14) What two reasons are there for an object not moving when a force is applied?
Too much mass or too much friction
15) What impact does friction have on the net force (total force) on an object?
Friction always acts in the opposite direction of motion, so it will always decrease the net
force
16) What is a “force”?
A push or pull
17) A bug hits a windshield. Describe the forces experience by each.
The bug pushes on the windshield, the windshield pushes back on the bug with the same
amount of force
18) Why doesn’t the person a gunfighter shoots go flying backwards? Explain in terms of
Newton’s 3rd Law.
A person is a large mass compared to a bullet. The bullet does not have enough force to
overcome the inertia of the body, so there is no net force. Basically, the bullet pushes on the
body and the body pushes back with that same amount of force – therefore no extra force to
cause motion
19) What has more force exerted on it in free fall, a bowling ball or a ping pong ball?
Explain your answer in terms of Newton’s 2nd Law.
The formula derived from Newton’s 2nd law is F=ma. Both balls have the same acceleration,
so the larger mass (bowling ball) has more force
20) If an elephant were chasing you, its enormous mass would be very threatening. But if
you zigzagged while running, the elephants mass would be advantageous to you getting
away. Explain why in Newton’s 1st Law.
The elephant has a lot of mass, therefore a lot of inertia. It will take a lot of force for the
elephant to change direction and start moving again.
Short Answer/Problem Solving
21) If an object is pushed with a force of 45N, but the net force is 15N, what do we know
about the frictional force? Why?
Givens
F =45 N
Net F = 15 N
Friction = ??
Formula
Net = Total – Friction
Calculations
15N = 45N - friction
friction = 30N
22) What force would you need to keep an object in constant motion (at a constant velocity)
if the frictional force is 20N?
Givens
Friction = 20N
Net = 0 (constant motion)
Force = ??
Formula
Net = Total – Friction
Calculations
0=force-20N
force 20N
23) What force would you need to apply if you want to accelerate an object from rest if the
frictional force was 5N?
Givens
Friction = 5N
Net >0
Force = ???
Formula
Net = Total – Friction
Calculations
0=force-5N
force > 5N
24) What is the force needed to accelerate a 28N object at a rate of 4m/s2?
Givens
Object = 28N
M=2.85 kg
A=4
F = ??
Formula
f=ma
Calculations
28N=m(9.8)
f=ma
f=(2.85)(4)
f=11.4N
25) What is the mass of an object that accelerates at a rate of 34m/s2 when a force of 12N is
applied?
Givens
M=??
A = 34 m/s2
F = 12N
Formula
Calculations
f=ma
12=m(34)
m=.35 kg
26) What is the acceleration of a 76kg object that moves due to a 180N force?
Givens
M=76 kg
A = ??
F = 180N
Formula
Calculations
f=ma
180=(76)a
a=2.37 m/s2
27) What is the mass of an object that has a 27N weight?
Givens
M=?? kg
A = 9.8
F = 27N
Formula
Calculations
f=ma
27=m(9.8)
m=2.76 kg
28) A sled with a mass of 50 kg is pulled along a flat, snow covered ground. The static
coefficient value of friction is .30 and the kinetic friction coefficient is .10.
d) What is the Force of Normal for the sled?
F=ma
f=(50)(9.8)
F (normal) = 490 /N
e) What force will be needed to start moving the sled?
Fn=490
U=Fs/Fn
Us=.3
Fs=???
.3=Fs/490
Fs = 147N
f) What force is needed to keep the sled moving?
Fn=490
U=Fk/Fn
Us=.3
Fk=???
.1=Fk/490
Fk = 49N
29) A boy exerts a 36 Newton force as he pulls a sled with a force of 52 N. What is the
coefficient value of kinetic friction between the rusty, metal sled runners and the partially
snow covered sidewalk?
Givens
Fn=52N
Us=??
Fk=36N
Formula
U=Fk/Fn
Calculations
Uk=36/52
Uk=.69
25) What is a Newton? Is it a measure of force or mass?
A newton is the measurement of force
30) Explain what “reaction” and “action” forces are. Give an example of each.
The action force is the action taken by the person/object. The reaction is the equal force
pushing in the opposite direction as the action taken.
A volleyball player hits (pushes) a volleyball, the volleyball pushes back on the player’s arm
31) If a sumo wrestler that weighs 378lbs. slams into another sumo wrestler that has a weight
of 343 lbs., explain the action and reaction forces of both wrestlers. Why would the
wrestlers not accelerate at the same rate upon impact?
Their forces are going in opposite directions, so the net force will be less. Once the wrestlers
are holding onto each other, the total mass increases, so the acceleration decreases
Behavior
32) A jet engine pushes air backwards as the plane moves forward down a
runway.
33) A meteor in deep space (not planets or stars around) flies in a straight
path.
34) A very heavy mousetrap vehicle may not move.
35) Two football players try to push a car out of the ditch, but it does not
move.
36) A skateboarder drags her foot on the ground to slow down.
37) A driver pushes on the gas pedal and the car goes faster.
38) A boy wobbles backwards as he catches a dodgeball thrown at him.
39) You punch a wall and it hurts!
40) A sky diver increases her speed the longer she falls.
41) You’re in equilibrium while sitting in your chair.
42) It takes longer to slow a motorhome to a stop than a small family car.
43) A dump truck moves faster after it has dumped its load of gravel.
Laws
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44) Bicycle racers bend over the handle bars to become as small as
possible during the race.
45) A Christmas ornament hangs from a tree branch, pulling the branch
down.
46) Christmas presents sitting under a Christmas tree stay there until
someone picks them up on Christmas morning.
1st 2nd 3rd
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