Question

If a spring has a constant of `4 (kg)/s^2`, how much work will it take to extend the spring by `65 cm`?

Answer 1

The work done is `0.845` joules.

Explanation:

We use the work equation for a spring, which states that,

`W=1/2kx^2`

• `k` is the spring constant in `"N/m"`

• `x` is the extension of the spring in meters

Note that:

`1 \ "N/m"=("kg m""/s"^2)/("m")=1 \ "kg/s"^2`

`:.4 \ "kg/s"^2=4 \ "N/m"`

So, we have:

`65 \ "cm"=0.65 \ "m"`

And so, the work done is:

`W=1/2*4 \ "N/m"*(0.65 \ "m")^2`

`=2 \ "N/m"*0.4225 \ "m"^2`

`=0.845 \ "N m"`

`=0.845 \ "J"`