Question

A baseball is thrown with an initial horizontal speed of 20 m/s, and an initial vertical speed of 10 m/s. Find the horizontal distance where the baseball will hit the ground, and the total time of fight. Assume g = 10 m/s2.

Answer 1

40m

2s

use: v = u + gt

at max height v = 0

- u = gt (g negative as it acts in opposite direction to ball motion which is upwards)

t = -u / -g = -10 / -10 = 1 second

total time of flight is twice this (provide we assume the ground is not sloping in any way)

total flight time is 2 secs

horizontal velocity (20ms-1) is constant as there is no accelerating for acting horizontally

s = vt

s = 20 × 2

s = 40m