Question

Suppose that Secretariat ran the Kentucky Derby with times of 25.3 5, 23.6 s, 23.5 s, and 23.6 s, for the quarter mile. (a) Find his average speed during each quarter-mile segment. first segment ft/s second segment It's a third segment it's fourth segment ft/s (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 start from rest.)

Answer 1

A quarter mile 1320 Ft a ) 1320 Ft First segment - 52.174 ft/s 25.3 s. second 1320 Ft segment 55.932 ft/s 23-6S 3rd segment 1320 Ft 56.17 ftis 23.55 55.932 ftis 4th Segment - 132074 Average speed during the 23.65: b) final quarter mile 55.932 ft/s acceleration average Final Vinitial time 55.932 0 (25.3 + 23.6 + 23.5 + 23.6) 0.582625 ft/s²