At the 18th green of the US Open, Tiger Woods needs to make a 20.5 ft (6.25 m) birdie putt to win the tournament. When he hits the ball, giving it an initial speed of 1.57 m/s, it stops 6.0 ft. (1.83 m) short of the hole. Assume the deceleration caused by the grass is constant, and calculate what initial speed Tiger should have hit his ball so that it just reached the hole.

Question

Henry · Answer

V^2 = Vo^2 + 2a.d a = (V^2-Vo^2)/2d a = (0-1.57^2)/2(6.25-1.83)=-0.279 m/s^2 Vo^2 = V^2-2a*d Vo^2= 0-2*(-0.279)*6.25 = 3.49 Vo = 1.87 m/s. Required.