Question

2. A father tries to pick up his son who weighs 60N. He applies an upward force of 40N on the boy. Which statement best describes the force experienced by the father from the boy? A. It is greater than 40 N

B. It is equal to 40 N

C. It is less than 40 N

D. The boy does not exert a force on the father

3. You push an 11 kg box to the right with a 33 N Force. The box moves to the right with a constant speed of 3 m/s. Based on the information, are there any other horizontal forces acting on the box?

A. No. 33 N of force is the force needed to move an 11kg object with a speed of 3m/s.

B. Yes. There must be a 33N force to left to yield a zero net horizontal force.

C. Yes. There must be a 22N force to left because of the difference between the pushing force and the weight of the box.

D. No. The box is moving with constant speed, so it has no forces acting on it.

4. 10kg girl is standing on a scale while riding in an elevator that is moving upward with a steady acceleration of 2 m/s2 up.  

What is the normal force exerted by the scale on the girl?

A.  120N

B.  100N

C.  80N  

D.  20N

E.  0N

5. A 10kg box is being pushed with a horizontal force of 40N.  The coefficient of static friction is 0.7 and for kinetic friction is 0.5. What is the magnitude of the friction force acting on the box?

A. 0 N B. 40 N C. 50 N D. 70 N E. 100 N

6. A 10kg box is being pushed with a horizontal force of 90N.  The coefficient of static friction is 0.7 and for kinetic friction is 0.5.  What is the magnitude of the friction force acting on the box as it slides across the floor?

A. 0 N B. 40 N C. 50 N D. 70 N E. 90 N

Answer 1