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The mass of a steel wrecking ball is 1.50 E3 kg. What power is used to raise it to a height of 40.0 m if the work is done in 20.0 seconds.


There are no choices and I have to show my work but I don't know how.

Verified Answer :

Livingsta

Given,

Mass of the ball (m) = 1.50 x 10³ kg = 1500 kg
Height raised = Displacement of the ball (D) = 40.0 m
Time taken (t) = 20 seconds

Power = Work done(W) ÷ time taken (t)

Work done (W) = Force (F) x Displacement (D)
Force (F) = Mass (m) x Acceleration due to gravity (g)
Acceleration due to gravity for earth (g) = 9.81 m/s²
Therefore,

Force (F) = 1500 x 9.8 = 14715 N

Work done = Force x Displacement = 14715 x 40 = 588600 Joules

Now, 
Power = Work done ÷ time taken = 588600 ÷ 20 = 29430 Watts

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