Wednesday, 21 September 2011

Power questions

Power questions

19 August 2011

17:30

PFY, p. 120

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Answers:

f) Power is the rate of doing work

Power (In Watts) = work done (in Joules) / time (in seconds)

g) 1 watt is the rate of working at one Joule per second

13. P = Wd/t = 1000/5 = 200W

14. P = Wd/t

Work done = force x distance = 300 x 2

P = 600/6 = 100W

15. P = Wd/t

Work done = f x d = 3000 x 10

P = 30000/4 = a) 7500W => b) 7.5kW

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