EIAT Forces, Torque, and Motion 3

Question 1

A 900 kg elevator car accelerates downward at 1.5 m/s². What is the net force acting on it? (g = 9.8 m/s²)

Accepted Answer

1,350 N downward

Answer

900 N downward

Answer

7,470 N downward

Answer

8,820 N downward

Question 2

What is the mechanical advantage of a pulley system that requires 250 N of effort to lift a 1,000 N load?

Accepted Answer

4

Answer

0.25

Answer

2

Answer

10

Question 3

A guide rail exerts a horizontal normal force on an elevator car. This force is best described as:

Accepted Answer

A reaction force perpendicular to the rail surface

Answer

A frictional force opposing motion

Answer

A gravitational force

Answer

A tension force along the rail

Question 4

If the rope speed in a traction elevator is 2 m/s and the sheave radius is 0.5 m, what is the sheave's angular velocity?

Accepted Answer

4 rad/s

Answer

1 rad/s

Answer

2.5 rad/s

Answer

5 rad/s

Question 5

During free fall, what does a person feel regarding their apparent weight?

Accepted Answer

Zero weight (weightlessness)

Answer

Normal weight

Answer

Doubled weight

Answer

Weight equal to mass only

Question 6

A brake applies a friction force of 800 N at a radius of 0.25 m on a drum. What braking torque is produced?

Accepted Answer

200 N·m

Answer

400 N·m

Answer

800 N·m

Answer

3,200 N·m

Question 7

Which quantity is conserved when no external torque acts on a rotating system?

Accepted Answer

Angular momentum

Answer

Kinetic energy

Answer

Linear momentum

Answer

Potential energy