EIAT - Elevator Industry Aptitude Forces, Torque, and Motion Questions and Answers

Question 1

An elevator motor needs to generate torque to lift the car.
If the radius of the motor's drive sheave is 0.5 meters and the force required to lift the elevator car and its contents is 8,000 Newtons, what is the minimum torque the motor must produce to begin lifting the car, ignoring friction and other losses?

Accepted Answer

4,000 N·m

Answer

2,000 N·m

Answer

16,000 N·m

Answer

8,000 N·m

Question 2

A technician is inside an elevator that is accelerating upwards at a constant rate. How does the normal force exerted by the elevator floor on the technician compare to the technician's actual weight (the force of gravity)?

Accepted Answer

The normal force is greater than their weight.

Answer

The normal force is less than their weight.

Answer

The normal force is equal to their weight.

Answer

The normal force is zero.

Question 3

A technician needs to slide a heavy, stationary piece of equipment across a machine room floor. Which of the following statements about the forces involved is most accurate?

Accepted Answer

The force required to start the equipment moving is greater than the force required to keep it sliding.

Answer

The force required to keep the equipment sliding is greater than the force required to start it moving.

Answer

Kinetic friction is the force that must be overcome to start the equipment moving.

Answer

The force of static friction and kinetic friction are always equal.

Question 4

In an elevator system, the motor provides the most torque during which phase of operation?

Accepted Answer

During initial acceleration from a stop.

Answer

During constant speed travel upwards.

Answer

When the elevator is stationary at a floor.

Answer

During constant speed travel downwards.

Question 5

An elevator car with a mass of 1,200 kg is perfectly balanced by a counterweight of 1,200 kg. Ignoring friction, what is the net force required from the hoisting machine to make the car travel upwards at a constant velocity?

Accepted Answer

0 N

Answer

11,760 N

Answer

1,200 N

Answer

23,520 N

Question 6

A technician uses a 1-meter long wrench to tighten a bolt, applying a force of 300 N at the very end of the wrench handle. To generate the same amount of torque, what force would be required if the technician could only grip the wrench at the 0.5-meter mark?

Accepted Answer

600 N

Answer

150 N

Answer

300 N

Answer

1,200 N