SI Session 7 Concept Quiz: Forces

Kevin Houlihan 02/03/15

1. A 1000-kg box is pulled along a rough surface at a constant velocity of 10 m/s. Which of the following is correct?

a. The pulling force is higher than the frictional force

b. The pulling force is equal to the frictional force

c. The pulling force is lower than the frictional force

2. A 10-kg and 20-kg stationary balls are made to roll at the same velocity. Which of the following requires a bigger force to move?

a. the 10-kg ball

b. the 20-kg ball

c. the force is equal for both balls

3. When a car stops suddenly, you lurch forward. What is the direction of the force that acts on you?

a. a forward force

b. a backward force

c. no force

4. A 50-kg boy collides with a 80-kg man. Which exerts a bigger force upon impact?

a. The 50-kg boy

b. The 80-kg man

c. Neither, they both exert the same amount of force

A Net Force F acts on an object.

5. This means that

a. the object must be moving in the direction of F.

b. the object may be moving in any direction.

6. This also means that

a. the object must be accelerating in the direction of F. Kevin Houlihan 02/03/15

b. the object could be accelerating in any direction.

7. Consider a person standing in an elevator that is accelerating downward. The magnitude of the upward normal force exerted by the elevator floor on the person is

a. larger than

b. smaller than

c. equal to

the magnitude of the weight of the person.

8. A small sports car collides head-on with a massive truck.Which vehicle experiences the greater magnitude force during the collision?

a. The car.

b. The truck.

c. The answer depends on the speeds the vehicles were moving.

d. Both experience the same force during the collision.

9. Which vehicle experiences the greater magnitude acceleration during the collision?

a. The car.

b. The truck.

c. The answer depends on the speeds the vehicles were moving.

d. Both experience the same acceleration during the collision.

10. A box is sliding down a ramp. It is accelerating. What would be the Free Body Diagram of the forces on the box?

1 A 2 B Kevin Houlihan 02/03/15

3 C 4 D

11. A mass, m, is pushed with a horizontal force, F, on a horizontal surface. The coefficient of static friction is μs. The block does not move. The magnitude of the static friction force on the mass is

a. Μsmg

b. μsF