# physics

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A bicyclist starts a timed race at 6 mph In order to win, he must average 21 mph Assuming constant acceleration from the start, how fast must he be traveling at the end of the race?

• physics -

If the average must be 21,
(V1 + V2)/2 = 21

V1 + V2 = 42

V2 = 42 - V1 = 42 - 6 = ___ mph

V2 is the final velocity required
V1 is the initial velocity

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