# 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 ?

Jan 4, 2016

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)