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| Math Central | Quandaries & Queries |
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Question from jamie, a student: Jill and Matt run on a 400 meter long oval track. Jill and Matt each run 10 laps daily and both run in the same lane. One day Jill and Matt began at the same point, but ran around the track in opposite directions. Jill ran at a constant speed that was 2 meters per second faster than matts constant speed. Jill passed Matt for the first time in 40 seconds. Jill ran at a constant rate of how many meters per second? |
Hi Jamie,
Suppose Matt runs at m metres per second then Jill runs at m + 2 metres per second.
Jill and Matt stand back-to-back at the starting line, facing in opposite directions. The starting pistol goes off and they start running. The distance between them at the start is 400 metres and it is decreasing at a rate of m + m + 2 = 2m + 2 metres per second. In 40 seconds they meet. Write an equation relating these facts and solve for m.
Penny
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