Answer
There are two forces acting on the elevator. The force of gravity points straight down. The tension force from the cable points straight up. Since the elevator is moving at a constant speed, the acceleration is zero. Therefore, the net force is zero and the magnitude of the two forces must be equal.
Work Step by Step
There are two forces acting on the elevator. The force of gravity points straight down. The tension force from the cable points straight up. Since the elevator is moving at a constant speed, the acceleration is zero. Therefore, the net force is zero and the magnitude of the two forces must be equal.