Question

If a spring has a constant of `4 (kg)/s^2`, how much work will it take to extend the spring by `87 cm`?

Answer 1

Here,work done is equals to the energy stored in the spring as elastic potential energy = `1/2 k x^2`

Given, `k= 4,x=87/100`

So,work done = `1.5138 J`

ALTERNATIVELY

Force required to stretch the spring is `F=kx`

So,work done here is `dW = F.ds=kxdx`

So,integrating from `W=0 to W` and `x=0 to 87/100`

`W= 1/2 kx^2 = 1.5138 J`