In april 1974, steve prefontaine completed a 10 km race in a time of 27 min, 43.6 s. suppose "pre" was at the 8.13 km mark at a time of 25.0 min. if he accelerated for 60 s and then maintained his increased speed for the remainder of the race. calculate his acceleration over the 60 s interval. assume his instantaneous speed at the 8.13 km mark was the same as his overall average speed up to that time.

Answer: it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.explanation:   we have equation of motion ,where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.average velocity = displacement/ time taken.average velocity = 10.69 miles/hr = 10.69*1.6*1000/(60*60) = 4.75 m/s4.75 = s/ts = 4. 1we also have acceleration = 2.18 m/s², initial velocity = 0 m/sso it will take   4.36 seconds to reach her average velocity 10.69 miles/hour.