An elevator cage of mass is lifted vertically upward by a constant cable tension of
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
An elevator cage of mass 600kg is lifted vertically upward by a constant cable tension of 7.5kN. Starting from rest, the cage rises through a height of 15m. Neglect air resistance and take g=9.8ms−2.
(i) Calculate the work done by the cable tension during the 15m ascent.
(ii) Determine the work done by the gravitational force over the same displacement.
(iii) Hence obtain the speed of the elevator cage after it has risen 15m.
(iv) Suppose the cable suddenly snaps at that instant. Assuming no other forces except gravity now act, find the additional height the cage will rise before momentarily coming to rest.