Find the spring constant for a spring that stretches 1.4cm when a 638 g weight is attached to it. how much work is done as the spring extends?

Spring constant: .

Work done: .

Explanation:

Convert all values to SI units.

Assume that the spring-mass system is vertical and is placed on the surface of the earth. The gravitational acceleration constant will be equal to .

Gravitational pull on the weight:

.

That's also the size of the force on the spring. .

The spring constant is the size of the force required to deshape the spring (by stretching, in this case) by unit length.

.

Assume that there's no energy loss in this process. The work done on the spring is the same as the elastic potential energy that it gains:

.

dynamic equilibrium is the answer.