Question

a cricket ball is hit so that it travels straight up in air and it requires 3 seconds to reach the maximum height its initial velocity is
a)10m/s b)15 m/s c)29.4m/s d)12.2 m/s

Answer 1

v = u - gt

At maximum heitht, v = 0

0 = u - (9.8)(3)

u = 29.4 m/s initial velocity

Answer 2

Initial velocity of the cricket ball is (c) 29.4 m/s

• For a body thrown vertically upwards, the time to reach maximum height is given by

                    t = u/g          ------------------------(1)

                    t = time of travel = 3 s

                    u = initial velocity

                    g = acceleration due to gravity = 9.8 m/$s^{2}$

• At maximum height, final velocity is zero.
• From (1), the initial velocity is

                   u = gt

                      = (9.8)(3)

                      = 29.4 m/s