A child drops a ball onto the road 28 m in front of a car travelling at 50 km/h. If the car can decelerate at a rate of 3.5 m/s2, will it stop before hitting the ball?

Question

A child drops a ball onto the road 28 m in front of a car travelling at 50 km/h.  If the car can decelerate at a rate of 3.5 m/s2, will it stop before hitting the ball?

Henry · Answer

Vc = 50km/h = 50000m/3600s = 13.89 m/s. d = (Vf^2-Vo^2)/2a. d = (0-(13.89)^2) / -7 = 27.56 m. Yes, it will stop before hitting the ball; but it will be very close!