A person of mass is standing upright on a spring balance placed on the floor of an…
PHYSICS · Multi-part · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A person of mass 60kg is standing upright on a spring balance placed on the floor of an elevator. Assume g=9.8ms−2.
(i) Draw a separate free-body diagram of the person for each of the following four situations:
(a) the elevator is at rest,
(b) the elevator is moving upward with a uniform velocity,
(c) the elevator is accelerating upward at 2ms−2,
(d) the elevator is accelerating downward at 2ms−2.
(ii) For each case (a) to (d) stated in part (i), state whether the reading of the spring balance is greater than, equal to, or less than the true weight of the person, and explain your answer with reference to the forces shown in the corresponding free-body diagram.