When a mass m1is placed on top of a spring and allowed to come to rest, the spring iscompressed by an amount x1. How much would the spring compress if it is an elevatoraccelerating upwards at 3g and has a mass of 4m1placed on top of the spring?

x₂ = 16 g m₂ / k

Explanation:

The spring in all cases must comply with Hooke's law

F = k x

Newton's diagram for equilibrium has

F - W = 0

k x₁ = m₁ g

k = g m₁ / x₁

When the elevator moves you have a clarification

F-W = m a

F = m (g + a)

Compression is

K x₂ = 4 m (g + 3g)

x₂ = 4m / k (4g)

x₂ = 16m2 / k g