Simple question about the power generated by an elevator motor

AI Thread Summary
The discussion revolves around calculating the mass of an elevator based on its motor power output of 12,000 Watts and a constant speed of 2 m/s. The user initially attempted to derive the mass using the formula m = P / (a * v), where gravitational acceleration is approximated at 9.8 m/s². However, the calculated mass of 612 kg does not match any of the provided answer choices. Participants suggest rounding to the nearest option, which is 500 kg, and advise submitting this answer while noting the discrepancy. The consensus is that the question may need to be reconsidered due to the mismatch in options.
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Homework Statement



The motor of an elevator generates 12000 Watts of power when moving the elevator at constant speed of 2 m/s.what is the mass of elevator in kg ...??

There are 5 options for the answer.

a) 500 Kg b) 400 Kg c) 300 Kg d) 240 Kg e) 200 Kg


Homework Equations



P = W/t

The Attempt at a Solution




I tried to solve it like this ..

Power = Work / Time = Force * Displacement / Time = Force * Velocity = m*a*v

So m = P / a*v

where a is the gravitaional acceleration = 9.8 m/s2
v is the constant speed = 2 m/s
P is the power = 12,000 Watts

I simply plugged in the numbers & got 612 Kg which is obviously wrong. Any help would be apprecitaed. Thanks
 
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It looks good to me, even if you use g=10m/s^2, the answer is 600 and not among the choices.
 
thx for ur responding.

So shall i take the nearest answer which is 500 Kg or what ..??
 
Go ahead and answer 500, and take your work to the prof. Unless I'm missing something..the question will get kicked out.
 
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