# Power question

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#1
Can somebody please help me with this mechanical power question? Im not quite sure how to do it!

0
3 years ago
#2
From the graph, you can work out the velocity. Does that help?
0
3 years ago
#3
(Original post by JakeRStudent)
Can somebody please help me with this mechanical power question? Im not quite sure how to do it!

Power is energy produced per second. Power = Energy/Time = Joules/second

Reading from the graph, the train accelerates from 0 to 40m/s in 180 seconds. The acceleration is constant until 180 seconds.

Because of that, after 90 seconds, the train must be travelling at 20 m/s.

So now use the formula for kinetic energy (K.E.) to work out the energy converted in the process of getting the train to travel at 20 m/s.

With that answer, use the power formula above to find the answer.
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