Physics homework. help me!

Question

A crane lifts a 200kg crate at constant velocity through a height of 50m in 155s. What's the power output to lift the crate?

Answer 1

Mass of the crane,m = 200 kg

Height,h = 50 m

Time,t = 155 s

Acceleration due to gravity,g = 9.81 m/s^2

Calculate the potential energy by using the formula:

PE = mgh

      =(200)(9.81)(50)

      =98100 J

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Calculate the power:

P = PE/t

   =98100/155

   = 633 W