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# M2 Power Question Watch

1. 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

2. 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
3. (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!

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