#### A marathon runner completes a 42.188-km course in 2 h, 30 min, and 12 s. There is an uncertainty of 25 m in the distance traveled and an uncertainty of 1 s in the elapsed time.

(a) Calculate the percent uncertainty in the distance.

(b) Calculate the uncertainty in the elapsed time.

(c) What is the average speed in meters per second?

(d) What is the uncertainty in the average speed?

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a) The percent uncertainty in the distance is

b) The uncertainty in time is

c) The average speed is

d) The percent uncertainty in the speed is the combination of uncertainties of distance and time.

Therefore, the uncertainty in the speed is

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