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# Power question watch

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

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2. From the graph, you can work out the velocity. Does that help?
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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