A sprinter accelerates at 4 m/s2 for 3 seconds, and then runs the rest of the race at a constant speed. If the race is 100 m, how much time does the sprinter take to finish the race?

Question

A sprinter accelerates at 4 m/s2 for 3 seconds, and then runs the rest of the race at a constant speed. If the race is 100 m, how much time does the sprinter take to finish the race?

Force · Answer

1/2(acceleration)(time^2)=distance 1/2(4 m/s^2)(3s)^2= 18m 100m-18m= 82m (total distance remaining) Time= Distance/speed Time= 82m/12m/s = 6.83s Time= 6.83s + 3s= 9.83s

A sprinter accelerates at 4 m/s2 for 3 seconds, and then runs the rest of the race at a constant speed. If the race is 100 m, how much time does the sprinter take to fi�nish the race?