a) Divide 0.25 miles by the time for each quarter. That will give you the average speed for each quarter in miles/sec. Multiply that by 5280 for feet/sec.
b) Divide the finish line (last quarter average) speed by the total race time for the average acceleration.
Whoever dreamed up this question apparently did not realize that the Kentucky Derby distance is 1 1/4 miles, not one mile. Someone left out the time of one of the quarter miles. The answer you get assuming this to be a mile race will be wrong.
Secretariat ran the Kentucky Derby with times for the quarter mile of 25.2 s, 24.0 s, 23.8 s, and 23.0 s. (a) Find his average speed during each quarter-mile segment. (b) Assuming that Secretariat's instantaneous speed at the finish line was the same as the average speed during the final quarter mile, find his average acceleration for the entire race. (Hint: Recall that horses in the Derby starts from rest.)
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