Question

A ball is thrown horizontally from a point 24m above the ground strikes the ground after travelling horizontally a distance of 18m with what speed vo was it thrown?

Answer 1

Answer:8.14 m/s

Explanation:

Given

height from which ball is thrown is $h=24\ m$

horizontal distance moved by ball $x=18\ m$

suppose $u_x$ is the speed by which ball is thrown horizontally

thus

vertical distance traveled in time t is given by

$h=ut+\frac{1}{2}at^2$

$24=0=\frac{1}{2}gt^2$

$t=\sqrt{\frac{2\times 24}{9.8}}$

$t=2.21\ s$

horizontal distance is given by

$R=u_x\times t$

$18=u_x\times 2.21$

$u_x=8.14\ m/s$