A spring is attached to the ceiling of an elevator and a block of mass M is suspended from the spring. In Case A, the elevator moves up with a constant speed of 5 m/s. In Case B, the elevator moves downward with a constant speed of 10 m/s. Will the string be stretched more in Case A or Case B or is the stretch the same in both cases? Explain.
1 answer
The string will be stretched more in Case B. This is because when the elevator moves downward, the block of mass M is accelerated downward due to gravity, and the spring must stretch to absorb the additional energy. When the elevator moves upward, the block of mass M is decelerated due to gravity, and the spring must compress to absorb the energy. Therefore, the spring will be stretched more in Case B.