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M2 Power Question

Hi, so I've done the first part of the question and am happy with it however I can't do the second part. Apparently the greatest speed is when the driving force is equal to the resistive force but why is this? Why can't it be more?Thanks :smile:

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Reply 1
Because a=0 when you reach maximum speed. Therefore, using f=ma, a can only equal 0 when the forces are equal to zero (cancel each other out) so the resistance force has to be equal to the driving force at that point in time
Reply 2
Original post by ak111
Because a=0 when you reach maximum speed. Therefore, using f=ma, a can only equal 0 when the forces are equal to zero (cancel each other out) so the resistance force has to be equal to the driving force at that point in time


Brilliant, thank you! :smile:

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