Answer:
The spring is compressed 7.15 meters.
Explanation:
Let us assume that the mass of the car, m = 41000 kg
Position of the tracks, h = 21 m
Spring constant of the spring, acceleration due to gravity,
Let the spring is compressed by a distance of x in stopping the ore car. In this case, the potential energy is balanced by the increase in spring potential energy such that :
So, the spring is compressed 7.15 meters.