Question 1

A 5.0-kg crate is on an incline that makes an angle 30with the horizontal. If the coefficent of static friction is 0.5, the maximum force that can be applied parallel to the plane without moving the crate is:

Accepted Answer

A)   0
B)   3.3 N
C)   30 N
D)   46 N
E)   55 N

Question 2

An object of mass m and another object of mass 2m are each forced to move along a circle of radius 1.0 m at a constant speed of 1.0 m/s. The magnitudes of their accelerations are:

Accepted Answer

A)   equal
B)   
C)   in the ratio of 2 : 1
D)   in the ratio of 4 : 1
E)   zero

Question 3

A 5.0-kg crate is resting on a horizontal plank. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.40. After one end of the plank is raised so the plank makes an angle of 30 with the horizontal, the force of friction is:

Accepted Answer

A)   0
B)   18 N
C)   21 N
D)   22 N
E)   44 N

Question 4

A forward horizontal force of 12 N is used to pull a 240-N crate at constant velocity across a horizontal floor. The coefficient of friction is:

Accepted Answer

A)   0.5
B)   0.05
C)   2
D)   0.2
E)   20

Question 5

A horizontal shove of at least 200-N is required to start moving a 800-N crate initially at rest on a horizontal floor. The coefficient of static friction is:

Accepted Answer

A)   0.25
B)   0.125
C)   0.50
D)   4.00
E)   none of these

Question 6

At what angle should the roadway on a curve with a 50m radius be banked to allow cars to negotiate the curve at 12 m/s even if the roadway is icy (and the frictional force is zero) ?

Accepted Answer

A)   0
B)   16°
C)   18°
D)   35°
E)   73°

Question 7

Block A, with a mass of 10 kg, rests on a 302, up B)  0.20 m/s2, down C)  2.8 m/s2, up D)  2.8 m/s2, down E)  0" class="answers-bank-image d-inline" rel="preload" > incline. The coefficient of kinetic friction is 0.20. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. Block B, with a mass of 3.0 kg, is attached to the dangling end of the string. The acceleration of B is: 2, up B)  0.20 m/s2, down C)  2.8 m/s2, up D)  2.8 m/s2, down E)  0" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   0.20 m/s2, up
B)   0.20 m/s2, down
C)   2.8 m/s2, up
D)   2.8 m/s2, down
E)   0 A

Question 8

A boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force g is the magnitude of the force of gravity. Which of the following must be true?   A)  P = f and N = Fg B)  P = f and N > Fg C)  P > f and N g  D)  P > f and N = Fg  E)  none of these" class="answers-bank-image d-inline" rel="preload" > as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and Fg is the magnitude of the force of gravity. Which of the following must be true? g is the magnitude of the force of gravity. Which of the following must be true?   A)  P = f and N = Fg B)  P = f and N > Fg C)  P > f and N g  D)  P > f and N = Fg  E)  none of these" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   P = f and N = Fg
B)   P = f and N > Fg
C)   P > f and N g 
D)   P > f and N = Fg 
E)   none of these

Question 9

An object moves around a circle. If the radius is doubled keeping the speed the same then the magnitude of the contripetal force must be:

Accepted Answer

A)   twice as great
B)   half as great
C)   four times as great
D)   one-fourth as great
E)   the same

Question 10

A horizontal force of 12 N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. If  μ\muμ s = 0.6 and  μ\muμ k = 0.80, the acceleration of the book in m/s2 is:

Accepted Answer

A)   0
B)   9.4 m/s2
C)   9.8 m/s2
D)   14.4 m/s2
E)   19.2 m/s2

Question 11

A 12-kg crate rests on a horizontal surface and a boy pulls on it with a force that is 30 below the horizontal. If the coefficient of static friction is 0.40, the minimum magnitude force he needs to start the crate moving is:

Accepted Answer

A)   44 N
B)   47 N
C)   54 N
D)   56 N
E)   71 N

Question 12

The driver of a 1000-kg car tries to turn through a circle of radius 100 m on an unbanked curve at a speed of 10 m/s. The actual frictional force between the tires and a slippery road has a magnitude of 900 N. The car:

Accepted Answer

A)   slides into the inside of the curve
B)   makes the turn
C)   slows down due to the frictinal force
D)   makes the turn only if it goes faster
E)   slides off to the outside of the curve

Question 13

A block is placed on a rough wooden plane. It is found that when the plane is tilted 30to the horizontal, the block will slide down at constant speed. The coefficient of kinetic friction of the block with the plane is:

Accepted Answer

A)   0.500
B)   0.577
C)   1.73
D)   0.866
E)   4.90

Question 14

If a certain car, going with speed v1, rounds a level curve with a radius R1, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:

Accepted Answer

A)   2R1
B)   4R1
C)   R1/2
D)   R1/4
E)   R1

Question 15

A ball is thrown downward from the edge of a cliff with an initial speed that is three times the terminal speed. Initially its acceleration is

Accepted Answer

A)   upward and greater than g
B)   upward and less than g
C)   downward and greater than g
D)   downward and less than g
E)   downward and equal to g

Question 16

Block A, with mass mA, is initially at rest on a horizontal floor. Block B, with mass mB, is initially at rest on the horizontal top surface of A. The coefficient of static friction between the two blocks is  μ\muμ s. Block A is pulled with a horizonatal force. It begins to slide out from under B if the force is greater than:

Accepted Answer

A)   mAg
B)   mBg
C)    μ\muμ smAg
D)    μ\muμ smBg
E)    μ\muμ s ( mA + m
B)  g  E

Question 17

A force  (larger than the largest possible force of static friction)  is applied to the left to an object moving to the right on a horizontal surface. Then:

Accepted Answer

A)   the object must be moving at constant speed
B)    and the friction force act in opposite directions
C)   the object must be slowing down
D)   the object must be speeding up
E)   the object must come to rest and remain at rest

Question 18

A bureau rests on a rough horizontal surface ( μ\muμ s = 0.50,  μ\muμ k = 0.40) . A constant horizontal force, just sufficient to start the bureau in motion, is then applied. The acceleration of the bureau is:

Accepted Answer

A)   0
B)   0.98 m/s 2
C)   3.3 m/s 2
D)   4.5 m/s 2
E)   8.9 m/s 2

Question 19

Block A, with a mass of 10 kg, rests on a 302, up the plane B)  0.69 m/s2, down the plane C)  2.6 m/s2, up the plane D)  2.6 m/s2, down the plane E)  0" class="answers-bank-image d-inline" rel="preload" > incline. The coefficient of kinetic friction is 0.20. The attached string is parallel to the incline and passes over a massless, frictionless pulley at the top. Block B, with a mass of 8.0 kg, is attached to the dangling end of the string. The acceleration of B is: 2, up the plane B)  0.69 m/s2, down the plane C)  2.6 m/s2, up the plane D)  2.6 m/s2, down the plane E)  0" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   0.69 m/s2, up the plane
B)   0.69 m/s2, down the plane
C)   2.6 m/s2, up the plane
D)   2.6 m/s2, down the plane
E)   0 B

Question 20

A ball is thrown upward into the air with a speed that is greater than terminal speed. On the way up it slows down and, after its speed equals the terminal speed but before it gets to the top of its trajectory:

Accepted Answer

A)   its speed is constant
B)   it continues to slow down
C)   it speeds up
D)   its motion becomes jerky
E)   none of the above

Exam 6: Force and Motion II

A 5.0-kg crate is on an incline that makes an angle 30with the horizontal. If the coefficent of static friction is 0.5, the maximum force that can be applied parallel to the plane without moving the crate is:

Correct Answer
verified

An object of mass m and another object of mass 2m are each forced to move along a circle of radius 1.0 m at a constant speed of 1.0 m/s. The magnitudes of their accelerations are:

Correct Answer
verified

A 5.0-kg crate is resting on a horizontal plank. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.40. After one end of the plank is raised so the plank makes an angle of 30 with the horizontal, the force of friction is:

Correct Answer
verified

A forward horizontal force of 12 N is used to pull a 240-N crate at constant velocity across a horizontal floor. The coefficient of friction is:

Correct Answer
verified

A horizontal shove of at least 200-N is required to start moving a 800-N crate initially at rest on a horizontal floor. The coefficient of static friction is:

Correct Answer
verified

At what angle should the roadway on a curve with a 50m radius be banked to allow cars to negotiate the curve at 12 m/s even if the roadway is icy (and the frictional force is zero) ?

Correct Answer
verified

Correct Answer
verified
A

A boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and F_gis the magnitude of the force of gravity. Which of the following must be true?

Correct Answer
verified

An object moves around a circle. If the radius is doubled keeping the speed the same then the magnitude of the contripetal force must be:

Correct Answer
verified

A horizontal force of 12 N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. If $\mu$ _s = 0.6 and $\mu$ _k = 0.80, the acceleration of the book in m/s²is:

Correct Answer
verified

A 12-kg crate rests on a horizontal surface and a boy pulls on it with a force that is 30 below the horizontal. If the coefficient of static friction is 0.40, the minimum magnitude force he needs to start the crate moving is:

Correct Answer
verified

The driver of a 1000-kg car tries to turn through a circle of radius 100 m on an unbanked curve at a speed of 10 m/s. The actual frictional force between the tires and a slippery road has a magnitude of 900 N. The car:

Correct Answer
verified

A block is placed on a rough wooden plane. It is found that when the plane is tilted 30to the horizontal, the block will slide down at constant speed. The coefficient of kinetic friction of the block with the plane is:

Correct Answer
verified

If a certain car, going with speed v₁, rounds a level curve with a radius R₁, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:

Correct Answer
verified

A ball is thrown downward from the edge of a cliff with an initial speed that is three times the terminal speed. Initially its acceleration is

Correct Answer
verified

Correct Answer
verified
E

A force (larger than the largest possible force of static friction) is applied to the left to an object moving to the right on a horizontal surface. Then:

Correct Answer
verified

A bureau rests on a rough horizontal surface ( $\mu$ _s = 0.50, $\mu$ _k = 0.40) . A constant horizontal force, just sufficient to start the bureau in motion, is then applied. The acceleration of the bureau is:

Correct Answer
verified

Correct Answer
verified
B

A ball is thrown upward into the air with a speed that is greater than terminal speed. On the way up it slows down and, after its speed equals the terminal speed but before it gets to the top of its trajectory:

Correct Answer
verified

Exam 6: Force and Motion II

A 5.0-kg crate is on an incline that makes an angle 30with the horizontal. If the coefficent of static friction is 0.5, the maximum force that can be applied parallel to the plane without moving the crate is:

Correct AnswerverifiedShow Answer

An object of mass m and another object of mass 2m are each forced to move along a circle of radius 1.0 m at a constant speed of 1.0 m/s. The magnitudes of their accelerations are:

Correct AnswerverifiedShow Answer

A 5.0-kg crate is resting on a horizontal plank. The coefficient of static friction is 0.50 and the coefficient of kinetic friction is 0.40. After one end of the plank is raised so the plank makes an angle of 30 with the horizontal, the force of friction is:

Correct AnswerverifiedShow Answer

A forward horizontal force of 12 N is used to pull a 240-N crate at constant velocity across a horizontal floor. The coefficient of friction is:

Correct AnswerverifiedShow Answer

A horizontal shove of at least 200-N is required to start moving a 800-N crate initially at rest on a horizontal floor. The coefficient of static friction is:

Correct AnswerverifiedShow Answer

At what angle should the roadway on a curve with a 50m radius be banked to allow cars to negotiate the curve at 12 m/s even if the roadway is icy (and the frictional force is zero) ?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedA

A boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and Fg is the magnitude of the force of gravity. Which of the following must be true?

Correct AnswerverifiedShow Answer

An object moves around a circle. If the radius is doubled keeping the speed the same then the magnitude of the contripetal force must be:

Correct AnswerverifiedShow Answer

A horizontal force of 12 N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. If μ\muμ s = 0.6 and μ\muμ k = 0.80, the acceleration of the book in m/s2 is:

Correct AnswerverifiedShow Answer

A 12-kg crate rests on a horizontal surface and a boy pulls on it with a force that is 30 below the horizontal. If the coefficient of static friction is 0.40, the minimum magnitude force he needs to start the crate moving is:

Correct AnswerverifiedShow Answer

The driver of a 1000-kg car tries to turn through a circle of radius 100 m on an unbanked curve at a speed of 10 m/s. The actual frictional force between the tires and a slippery road has a magnitude of 900 N. The car:

Correct AnswerverifiedShow Answer

A block is placed on a rough wooden plane. It is found that when the plane is tilted 30to the horizontal, the block will slide down at constant speed. The coefficient of kinetic friction of the block with the plane is:

Correct AnswerverifiedShow Answer

If a certain car, going with speed v1, rounds a level curve with a radius R1, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:

Correct AnswerverifiedShow Answer

A ball is thrown downward from the edge of a cliff with an initial speed that is three times the terminal speed. Initially its acceleration is

Correct AnswerverifiedShow Answer

Correct AnswerverifiedE

A force (larger than the largest possible force of static friction) is applied to the left to an object moving to the right on a horizontal surface. Then:

Correct AnswerverifiedShow Answer

A bureau rests on a rough horizontal surface ( μ\muμ s = 0.50, μ\muμ k = 0.40) . A constant horizontal force, just sufficient to start the bureau in motion, is then applied. The acceleration of the bureau is:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedB

A ball is thrown upward into the air with a speed that is greater than terminal speed. On the way up it slows down and, after its speed equals the terminal speed but before it gets to the top of its trajectory:

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
A

A boy pulls a wooden box along a rough horizontal floor at constant speed by means of a force as shown. In the diagram f is the magnitude of the force of friction, N is the magnitude of the normal force, and F_gis the magnitude of the force of gravity. Which of the following must be true?

Correct Answer
verified

Correct Answer
verified

A horizontal force of 12 N pushes a 0.50-kg book against a vertical wall. The book is initially at rest. If $\mu$ _s = 0.6 and $\mu$ _k = 0.80, the acceleration of the book in m/s²is:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

If a certain car, going with speed v₁, rounds a level curve with a radius R₁, it is just on the verge of skidding. If its speed is now doubled, the radius of the tightest curve on the same road that it can round without skidding is:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
E

Correct Answer
verified

A bureau rests on a rough horizontal surface ( $\mu$ _s = 0.50, $\mu$ _k = 0.40) . A constant horizontal force, just sufficient to start the bureau in motion, is then applied. The acceleration of the bureau is:

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified