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If I lift 40 kg 6 times 60 centimeters, is that 40*6*0,6*9,82 Joule? And then if I take the time into account, I will know the Watts? Or did I misunderstand?

The background is that I read that you can use the work from exercising to power energy, and I find that one set that I do is 50 Watts approximately. So if I theoretically could find a way to use the work I do, that would be 50 Watt?

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    $\begingroup$ A joule is equal to the energy transferred (or work done) to an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or N. m). A Watt is the amount of Joules over the time the energy was expended, that is, power. $\endgroup$ – user108787 Aug 1 '16 at 13:37
  • $\begingroup$ @count_to_10 My result is that I can power 50 Watts from weight lifting. Is that correct? My calculation is 40 kg, lift it 60 centimeters, 6 repitions, in 30 seconds. The result is approx. 50. But I'm not sure my modelling is correct. $\endgroup$ – Niklas Aug 1 '16 at 13:39
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    $\begingroup$ The work is done by you on the boxes and it the work from you have been transferred to the boxes as potential energy, you are using the work to lift the box so now to find use if that work you need to take work from the boxes. Suppose you drop the box from that height and it presses the ground where presses sensors are placed to convert force into electricity, so this is one way your work will produce some good effect. $\endgroup$ – Rohit Joshi Aug 1 '16 at 13:40
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    $\begingroup$ 1728.org/energy.htm is a calculator for this. The velocity is your estimate of how long it took to lift the weight 60 cm, 0.6m. $\endgroup$ – user108787 Aug 1 '16 at 13:45
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No you did not misunderstand, your calculation is correct. You have done 1414 J of work in lifting the weights. Assuming this took about 30 s your average rate of working was 50 W. If you were to keep this up and you convert the energy into electricity, you could probably keep a desk lamp glowing!

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