Question 1

An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

Accepted Answer

A)  A constant force is being applied to it in the direction of motion.
B)  A constant force is being applied to it in the direction opposite of motion.
C)  A constant force is being applied to it perpendicular to the direction of motion.
D)  The net force on the object is zero.
E)  Its acceleration is in the same direction as it velocity.F) C) and D)
G) B) and D)

Question 2

A fireman is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireman. When the force on his hands equals his weight, what happens to the fireman?

Accepted Answer

A)  The fireman comes to a stop.
B)  The fireman descends with slower and slower speed.
C)  The fireman descends with a smaller but non-zero acceleration.
D)  The fireman continues to descend, but with constant speed.
E)  The acceleration of the fireman is now upward.F) A) and E)
G) B) and C)

Question 3

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

Accepted Answer

A)  75 N.
B)  7.5 N.
C)  750 N.
D)  any horizontal force greater than zero.E) A) and B)
F) A) and C)

Question 4

When a 45-kg person steps on a scale in an elevator, the scale reads a steady 410 N. Which of the following statements must be true? (There could be more than one correct choice.)

Accepted Answer

A)  The elevator is accelerating upward at a constant rate.
B)  The elevator is accelerating downward at a constant rate.
C)  The elevator is moving upward at a constant rate.
D)  From the given information, we cannot tell if the elevator is moving up or down.E) C) and D)
F) A) and B)

Exam 4: Forces and Newtons Laws of Motion

A fireman is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireman. When the force on his hands equals his weight, what happens to the fireman?

Correct Answer
verified

When a 45-kg person steps on a scale in an elevator, the scale reads a steady 410 N. Which of the following statements must be true? (There could be more than one correct choice.)

Correct Answer
verified

An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

Correct Answer
verified

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

Correct Answer
verified

Exam 4: Forces and Newtons Laws of Motion

A fireman is sliding down a fire pole. As he speeds up, he tightens his grip on the pole, thus increasing the vertical frictional force that the pole exerts on the fireman. When the force on his hands equals his weight, what happens to the fireman?

Correct AnswerverifiedShow Answer

When a 45-kg person steps on a scale in an elevator, the scale reads a steady 410 N. Which of the following statements must be true? (There could be more than one correct choice.)

Correct AnswerverifiedShow Answer

An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

Correct AnswerverifiedShow Answer

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified