A 1100-kg elevator is lifted at a constant speed of 1.5 m/s through a height of 20 m.

Part A
How much work is done by the tension in the elevator cable?
Express your answer to two significant figures and include appropriate units.
Part B
How much work is done by gravity?

Part A: To find the work done by the tension in the elevator cable, we can use the work-energy principle. The work done is equal to the change in the elevator's potential energy.

Work = Change in Potential Energy

Potential Energy = mass * gravitational acceleration * height

In this case, the mass of the elevator is 1100 kg, the height is 20 m, and the gravitational acceleration is approximately 9.8 m/s^2.

Work = 1100 kg * 9.8 m/s^2 * 20 m
= 215,600 J (to two significant figures)

Therefore, the work done by the tension in the elevator cable is approximately 215,600 Joules.

Part B: To find the work done by gravity, we can again use the work-energy principle. The work done by gravity is the negative of the change in potential energy.

Work = - Change in Potential Energy

As we calculated in Part A, the potential energy change is 215,600 J. Therefore, the work done by gravity is -215,600 Joules.

Note: The negative sign indicates that gravity is doing work in the opposite direction of the displacement of the elevator. In this case, gravity is acting downward while the elevator is being lifted upward.