How do I calculate the efficiency of a propeller using acceleration and voltage?

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To calculate the efficiency of a propeller using acceleration and voltage, first determine the force produced by the propeller based on the acceleration measured over a set distance. Incorporate friction by calculating the force using the trolley's weight and the coefficient of friction. The energy output from the power source can be calculated as voltage multiplied by current and time. To find the energy gained by the trolley, use the final kinetic energy formula, which is half the mass multiplied by the square of the final speed. This approach allows for an accurate assessment of the propeller's efficiency.
Kris2456
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For a project i had to make a propeller that pushes along a small trolley at different voltages.

I made the propeller and buggy, and i lay them on a wooden track. Using the time taken to accelerate across the 30cm track, i was able to find the acceleration, and hence the force that the propeller produces at that voltage.

Of course, to this i can add friction which is the weight of the trolley x Mu so as to find the total force that the propeller produces.

I also have to find the efficiency of the propeller. Now i know the Energy produced by the powerpack is V x A x t. But i am not sure how to find out how much energy was gained by the trolley during the time it took to cross the track. Can anyone help (bear in mind it is not traveling at a constant speed).

Thanks.
 
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If you found the acceleration, then the final speed is just the (constant) acceleration multiplied by the time. Since the initial speed was 0, the energy gained by the trolley is its final kinetic energy: (1/2)mv2 where v is the final speed.
 
Oh of course!
I forgot that the kinetic energy is equal to the speed at that point, not overall!
 
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