Find the power an electric motor

AI Thread Summary
To calculate the power required for an electric motor to assist a man riding a bike uphill, first determine the angle of the slope using the given ratio. Next, calculate the acceleration of the bike to find the force based on the combined mass of the man and the bike. The work done can be expressed as force multiplied by distance, and power can be derived by substituting velocity for distance in the work equation. It is essential to ensure that the force and velocity are considered constant for accurate calculations. This approach will yield the necessary power value for the motor.
Monsu
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hi, i need just a formula to go ahead with this. I am given two masses, m1 of man, and m2 of his bike. he is going up a hill with slope (sqroot3/3) and velocity (v). Now I need to find the power an electric motor would need to have for the man to b able to ride his bike up without pedalling.
Power = energy / time, right? how can i find the time? pls help urgently! :rolleyes:
 
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1) First, you must find the angle that the hill makes. Actually, you might be able to skip this step, but I couldn't and still logically produce the rest of the equation.

2) Secondly, find the acceleration on the bike.

3) Now you know the force (since you know the mass and acceleration), you can find the work involved in moving the bike any incremental distance.

4) To find the power, substitute velocity for distance in the work equation.

I believe this will provide you with the correct answer.
 
I just thought of another way to look at this:

Assuming these variable are constant enough for an integral to be a multiple,

Work is force times distance.

Velocity is distance divided by time.

Power is work divided by time. Therefore Power is force times distance divided by time.

This type of thinking ONLY works because force and velocity are constant. Since they are, though, it works :-p
 
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