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 #?

1 Answer
Jan 4, 2016

Answer:

W = 721 J

Explanation:

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