Question

How much work would it take to push a `2 kg` weight up a `9 m` plane that is at an incline of `pi / 4`?

Answer 1

I got `125J`

Explanation:

Let us consider the diagram:

with:
`alpha=pi/4`
`d=9m`

and the fact that the work done will result in an increase of Potential Energy (Gravitational) `U` so that:

`W=U=mgh`

but `h=dsin(alpha)`
so:

`W=mg*dsin(alpha)=2*9.8*9sin(pi/4)=124.7~~125J`