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The cable of a crane is lifting a 950 kg girder. The girder increases its speed from 0.25 m/s to 0.75 m/sin a distance of 5.5m
a) How much work is done by gravity?
b) How much work is done by tension?

Respuesta :

nobleswift

Explanation:

a) How much work is done by gravity?

  • w = f x d
  • w = 950 x 10 x 5.5 = 52250j

b) How much work is done by tension?

  • v²=u²+2as
  • 0.75²=0.25²+2a x5.5
  • 0.56=0.06+2a x5.5
  • 2a x5.5 = 0.56 - 0.06
  • 2a x 5.5 =0.5
  • 11a=0.5
  • a = 0.5/11 = 0.05m/s²

w = f x d

w = 950 x 0.05 x 5.5 = 261.25j

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