Question

How much work would it take to push a `8 kg` weight up a `13 m` plane that is at an incline of `pi / 4`?

Answer 1

W = 721 J

Explanation:

Assume the surface is frictionless. Therefore the only work done is against the weight.

`sin (π/4) = h/L`
`⇒ h = L sin(π/4) = 13 × sin (π/4) = 9.192… m`

Weight of the mass:
`w=mg = 8 × 9.8 = 78.4 N`

Work done against the weight:
`W=w×h = 78.4 × 9.192… = 720.68… = 721 J` (3 sf)