Newton S Law Quiz Study Guide

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Class/Period______

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

Newton’s 1stLaw
Newton’s 2nd Law
Newton’s 3rd Law
Static Friction
Kinetic Friction

Study Material

1)Notes

2)Problem Solving Practice

3)Study Guide

4)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?

GivensFormulaCalculations

22)What force would you need to keep an object in constant motion (at a constant velocity) if the frictional force is 20N?

GivensFormulaCalculations

23)What force would you need to apply if you want to accelerate an object from rest if the frictional force was 5N?

GivensFormulaCalculations

24)What is the force needed to accelerate a 28N object at a rate of 4m/s2?

GivensFormulaCalculations

25)What is the mass of an object that accelerates at a rate of 34m/s2 when a force of 12N is applied?

GivensFormulaCalculations

26)What is the acceleration of a 76kg object that moves due to a 180N force?

GivensFormulaCalculations

27)What is the mass of an object that has a 27N weight?

GivensFormulaCalculations

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?

GivensFormulaCalculations

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

Laws

32) A jet engine pushes air backwards as the plane moves forward down a runway. / 1st / 2nd / 3rd
33) A meteor in deep space (not planets or stars around) flies in a straight path. / 1st / 2nd / 3rd
34) A very heavy mousetrap vehicle may not move. / 1st / 2nd / 3rd
35) Two football players try to push a car out of the ditch, but it does not move. / 1st / 2nd / 3rd
36) A skateboarder drags her foot on the ground to slow down. / 1st / 2nd / 3rd
37) A driver pushes on the gas pedal and the car goes faster. / 1st / 2nd / 3rd
38) A boy wobbles backwards as he catches a dodgeball thrown at him. / 1st / 2nd / 3rd
39) You punch a wall and it hurts! / 1st / 2nd / 3rd
40) A sky diver increases her speed the longer she falls. / 1st / 2nd / 3rd
41) You’re in equilibrium while sitting in your chair. / 1st / 2nd / 3rd
42) It takes longer to slow a motorhome to a stop than a small family car. / 1st / 2nd / 3rd
43) A dump truck moves faster after it has dumped its load of gravel. / 1st / 2nd / 3rd
44) Bicycle racers bend over the handle bars to become as small as possible during the race. / 1st / 2nd / 3rd
45) A Christmas ornament hangs from a tree branch, pulling the branch down. / 1st / 2nd / 3rd
46) Christmas presents sitting under a Christmas tree stay there until someone picks them up on Christmas morning. / 1st / 2nd / 3rd

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

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?

GivensFormulaCalculations

F =45 NNet = Total – Friction15N = 45N - friction

Net F = 15 Nfriction = 30N

Friction = ??

22)What force would you need to keep an object in constant motion (at a constant velocity) if the frictional force is 20N?

GivensFormulaCalculations

Friction = 20NNet = Total – Friction0=force-20N

Net = 0 (constant motion)force 20N

Force = ??

23)What force would you need to apply if you want to accelerate an object from rest if the frictional force was 5N?

GivensFormulaCalculations

Friction = 5NNet = Total – Friction0=force-5N

Net >0force > 5N

Force = ???

24)What is the force needed to accelerate a 28N object at a rate of 4m/s2?

GivensFormulaCalculations

Object = 28Nf=ma28N=m(9.8)

M=2.85 kg

A = 4f=maf=(2.85)(4)

F = ??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?

GivensFormulaCalculations

M=??

A = 34 m/s2f=ma12=m(34)

F = 12Nm=.35 kg

26)What is the acceleration of a 76kg object that moves due to a 180N force?

GivensFormulaCalculations

M=76 kg

A = ??f=ma180=(76)a

F = 180Na=2.37 m/s2

27)What is the mass of an object that has a 27N weight?

GivensFormulaCalculations

M=?? kg

A = 9.8f=ma27=m(9.8)

F = 27Nm=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=maf=(50)(9.8)F (normal) = 490 /N

e)What force will be needed to start moving the sled?

Fn=490U=Fs/Fn.3=Fs/490

Us=.3Fs = 147N

Fs=???

f)What force is needed to keep the sled moving?

Fn=490U=Fk/Fn.1=Fk/490

Us=.3Fk = 49N

Fk=???

GivensFormulaCalculations

Fn=52NU=Fk/FnUk=36/52

Us=??Uk=.69

Fk=36N

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

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