How Much Electrical Power Does a 75% Efficient Pedal-Operated Generator Produce?

AI Thread Summary
The discussion revolves around calculating the electrical power produced by a 75% efficient pedal-operated generator driven by an 80kg man. The man climbs a staircase 3.0 meters high in 8.5 seconds, generating a force of 800N. The total work done is calculated as 2400J, leading to an initial power output of 282.4W. After accounting for the generator's efficiency, the final electrical power output is determined to be 211.8W. The calculations and methodology presented appear to be correct.
lemon
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Hi:
Would somebody please check to see if I am on the right track with this problem.
Many thanks

Homework Statement


An 80kg man on a step-exercise machine climbs a staircase 3.0m high in 8.5s. If he works at the same rate to drive a pedal-operated generator with an efficiency of 75%, how much electrical power would be produced?



Homework Equations


power=work done/time taken
efficiency=useful energy output/total energy input
work=force x displacement in direction of force
F=ma
weight=mg (gravity=10ms ^-2)



The Attempt at a Solution


F=80 x 10 =800N
Work done (W)=800 x 3.0 = 2400J
Power=2400/8.5 = 282.4W (1d.p.)
therefore
75% x 282.4 = 211.8W
F=
 
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looks good
 
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