Chapter 5, Problem 1CQ

An elevator suspended by a cable is descending at constant velocity. How many forcevector would be shown on a free-body diagram? Name them.

To determine

The force vectors acting on the elevator under given conditions

Explanation of Solution

The elevator is descending at a constant velocity.

Since the elevator is descending at a constant velocity, it experiences no acceleration. Therefore, the net force acting on the elevator is zero. The elevator is supported by the cable. Therefore, the tension of the cable acts upward. The other force on the elevator is its weight. The situation is explained by the free-body diagram given below.

  

When the net force acting on the elevator is zero and two forces act on it, both forces will be equal in magnitude and opposite in direction.

Conclusion:

There are two forces acting on the elevator when it is descending with a constant velocity. The forces are the tension of the cable and the weight of the elevator.