A 1440-kg crate of cabbages is laid on a level, frictionless track at the end of a heavy spring. The spring is compressed a distance of 0.100 m by a force of 83500 N. When the spring is released, it propels the crate. the spring constant of the spring equals 835000 N/m.

Question

A 1440-kg crate of cabbages is laid on a level, frictionless track at the end of a heavy spring. The spring is compressed a distance of 0.100 m by a force of 83500 N. When the spring is released, it propels the crate. the spring constant of the spring equals 835000 N/m. 
What is the total amount of work done by the spring on the crate during the launch in J?

bobpursley · Answer

spring constant=835000/.1 in N/m KE at launch= PE in spring work done by spring= 1/2 k (.1)^2