Question 1

A block is on a frictionless horizontal table,on earth.This block accelerates at  when a  horizontal force is applied to it.The block and table are then set up on the moon where the acceleration due to gravity is  .What is the weight of the block on the moon?

Accepted Answer

A)   77 N
B)   67 N
C)   58 N
D)   48 N
E)   39 N A

Question 2

A car is being towed at constant velocity on a horizontal road using a horizontal chain.The tension in the chain must be equal to the weight of the car in order to maintain constant velocity.

Accepted Answer

A) True 
 B)False  False

Question 3

You swing a bat and hit a heavy box with a force of 1500 N.The force the box exerts on the bat is

Accepted Answer

A)   exactly 1500 N only if the box does not move.
B)   exactly 1500 N whether or not the box moves.
C)   greater than 1500 N if the box moves.
D)   less than 1500 N if the box moves.
E)   greater than 1500 N if the bat bounces back. B

Question 4

Two objects,each of weight W,hang vertically by spring scales as shown in the figure.The pulleys and the strings attached to the objects have negligible weight,and there is no appreciable friction in the pulleys.The reading in each scale is

Accepted Answer

A)   W.
B)   more than W, but not quite twice as much.
C)   less than W.
D)   2W.
E)   more than 2W.

Question 5

A series of weights connected by very light cords are given an upward acceleration of  by a pull P,as shown in the figure.A,B,and C are the tensions in the connecting cords.The SMALLEST of the three tensions,A,B,and C,is closest to

Accepted Answer

A)   80.0 N.
B)   196 N.
C)   276 N.
D)   483 N.
E)   621 N.

Question 6

You are seated in a bus and notice that a hand strap that is hanging from the ceiling hangs away from the vertical in the backward direction.From this observation,you can conclude that

Accepted Answer

A)   the velocity of the bus is forward.
B)   the velocity of the bus is backward.
C)   You cannot conclude anything about the direction of the velocity of the bus.

Question 7

Point P in the figure indicates the position of an object traveling at constant speed clockwise around the circle.Which arrow best represent the direction the object would travel if the net external force on it were suddenly reduced to zero?

Accepted Answer

A)   
B)   
C)   
D)   
E)

Question 8

The graph in the figure shows the net force acting on a 3.0-kg object as a function of time.  (a)What is the acceleration of this object at time t = 2.0 s?
(b)Draw,to scale,a graph of the acceleration of this object as a function of time over the range  to  .

Accepted Answer

The answer of The graph in the figure shows the...

Question 9

The following four forces act on a 4.00 kg object:  1 = 300 N east  2 = 700 N north  3 = 500 N west  4 = 600 N south What is the acceleration of the object?

Accepted Answer

A)   224 N in a direction 63.4° north of west
B)   300 N in a direction 63.4° north of west
C)   300 N in a direction 26.6° north of west
D)   224 N in a direction 26.6° north of west
E)   2100 N in a direction 26.6° north of west

Question 10

A 1000-kg car is driving toward the north along a straight horizontal road at a speed of  .The driver applies the brakes and the car comes to a rest uniformly in a distance of  .What are the magnitude and direction of the net force applied to the car to bring it to rest?

Accepted Answer

A)   1.00 N north
B)   10.0 ×  N south
C)   1.00 ×  N south
D)   1.00 N south
E)   100 N south

Question 11

A box of mass 50 kg is at rest on a horizontal frictionless surface.A constant horizontal force F then acts on the box and accelerates it to the right.It is observed that it takes the box 6.9 seconds to travel 28 meters.What is the magnitude of the force?

Accepted Answer

The answer of A box of mass 50 kg is...

Question 12

Suppose you are playing hockey on a new-age ice surface for which there is no friction between the ice and the hockey puck.You wind up and hit the puck as hard as you can.After the puck loses contact with your stick,the puck will

Accepted Answer

A)   start to slow down.
B)   not slow down or speed up.
C)   speed up a little, and then slow down.
D)   speed up a little, and then move at a constant speed.

Question 13

On a horizontal frictionless floor,a worker of weight 0.900 kN pushes horizontally with a force of 0.200 kN on a box weighing 1.80 kN.As a result of this push,which statement could be true?

Accepted Answer

A)   The box will not move because the push is less than its weight.
B)   The worker and box will both have an acceleration of 1.08 m/s2, but in opposite directions.
C)   The worker and box will both have an acceleration of 2.17 m/s2, but in opposite directions.
D)   The worker will accelerate at 1.08 m/s2 and the box will accelerate at 2.17 m/s2, but in opposite directions.
E)   The worker will accelerate at 2.17 m/s2 and the box will accelerate at 1.08 m/s2, but in opposite directions.

Question 14

A 50.0-N box is sliding on a rough horizontal floor,and the only horizontal force acting on it is friction.You observe that at one instant the box is sliding to the right at  and that it stops in 2.25 s with uniform acceleration.What magnitude force does friction exert on this box?

Accepted Answer

A)   3.97 N
B)   8.93 N
C)   38.9 N
D)   50.0 N
E)   490 N

Question 15

A box of mass m is pulled with a constant acceleration a along a horizontal frictionless floor by a wire that makes an angle of 15° above the horizontal.If T is the tension in this wire,then

Accepted Answer

A)   T = ma.
B)   T > ma.
C)   T < ma.

Question 16

A 10,000-kg rocket blasts off from earth with a uniform upward acceleration of 2.00 m/s2 and feels no air resistance.The upward thrust force its engines must provide during this acceleration is closest to

Accepted Answer

A)   20,000 N.
B)   980,000 N.
C)   118,000 N.
D)   78,000 N.

Question 17

An object is moving to the right,and experiencing a net force that is directed to the right.The magnitude of the force is decreasing with time.The speed of the object is

Accepted Answer

A)   increasing.
B)   decreasing.
C)   constant in time.

Question 18

On its own,a certain tow-truck has a maximum acceleration of  .What would be the maximum acceleration when this truck was towing a bus of twice its own mass?

Accepted Answer

A)   2.5 m/s2
B)   2.0 m/s2
C)   1.5 m/s2
D)   1.0 m/s2

Question 19

The graph in the figure shows the x component of the acceleration of a 2.4-kg object as a function of time (in ms).  (a)At what time(s)does the x component of the net force on the object reach its maximum magnitude,and what is that maximum magnitude?
(b)What is the x component of the net force on the object at time  and at  ?

Accepted Answer

The answer of The graph in the figure shows the...

Question 20

Two forces act on a  object.One force has magnitude 65 N directed 59° clockwise from the positive x-axis,and the other has a magnitude 35 N at 32° clockwise from the positive y-axis.What is the magnitude of this object's acceleration?

Accepted Answer

A)   1.1 m/s2
B)   1.3 m/s2
C)   1.5 m/s2
D)   1.7 m/s2

Exam 4: Newtons Laws of Motion

A block is on a frictionless horizontal table,on earth.This block accelerates at when a horizontal force is applied to it.The block and table are then set up on the moon where the acceleration due to gravity is .What is the weight of the block on the moon?

A car is being towed at constant velocity on a horizontal road using a horizontal chain.The tension in the chain must be equal to the weight of the car in order to maintain constant velocity.

You swing a bat and hit a heavy box with a force of 1500 N.The force the box exerts on the bat is

Two objects,each of weight W,hang vertically by spring scales as shown in the figure.The pulleys and the strings attached to the objects have negligible weight,and there is no appreciable friction in the pulleys.The reading in each scale is

A series of weights connected by very light cords are given an upward acceleration of by a pull P,as shown in the figure.A,B,and C are the tensions in the connecting cords.The SMALLEST of the three tensions,A,B,and C,is closest to

You are seated in a bus and notice that a hand strap that is hanging from the ceiling hangs away from the vertical in the backward direction.From this observation,you can conclude that

Point P in the figure indicates the position of an object traveling at constant speed clockwise around the circle.Which arrow best represent the direction the object would travel if the net external force on it were suddenly reduced to zero?

The graph in the figure shows the net force acting on a 3.0-kg object as a function of time. (a)What is the acceleration of this object at time t = 2.0 s? (b)Draw,to scale,a graph of the acceleration of this object as a function of time over the range to .

The following four forces act on a 4.00 kg object: ₁ = 300 N east ₂ = 700 N north ₃ = 500 N west ₄ = 600 N south What is the acceleration of the object?

A 1000-kg car is driving toward the north along a straight horizontal road at a speed of .The driver applies the brakes and the car comes to a rest uniformly in a distance of .What are the magnitude and direction of the net force applied to the car to bring it to rest?

A box of mass 50 kg is at rest on a horizontal frictionless surface.A constant horizontal force F then acts on the box and accelerates it to the right.It is observed that it takes the box 6.9 seconds to travel 28 meters.What is the magnitude of the force?

Suppose you are playing hockey on a new-age ice surface for which there is no friction between the ice and the hockey puck.You wind up and hit the puck as hard as you can.After the puck loses contact with your stick,the puck will

On a horizontal frictionless floor,a worker of weight 0.900 kN pushes horizontally with a force of 0.200 kN on a box weighing 1.80 kN.As a result of this push,which statement could be true?

A 50.0-N box is sliding on a rough horizontal floor,and the only horizontal force acting on it is friction.You observe that at one instant the box is sliding to the right at and that it stops in 2.25 s with uniform acceleration.What magnitude force does friction exert on this box?

A box of mass m is pulled with a constant acceleration a along a horizontal frictionless floor by a wire that makes an angle of 15° above the horizontal.If T is the tension in this wire,then

A 10,000-kg rocket blasts off from earth with a uniform upward acceleration of 2.00 m/s² and feels no air resistance.The upward thrust force its engines must provide during this acceleration is closest to

An object is moving to the right,and experiencing a net force that is directed to the right.The magnitude of the force is decreasing with time.The speed of the object is

On its own,a certain tow-truck has a maximum acceleration of .What would be the maximum acceleration when this truck was towing a bus of twice its own mass?

Two forces act on a object.One force has magnitude 65 N directed 59° clockwise from the positive x-axis,and the other has a magnitude 35 N at 32° clockwise from the positive y-axis.What is the magnitude of this object's acceleration?