Question

A stone is thrown horizontally at 15 m/s from the top of a cliff 40 meters high. How far from the base does the stone hit the ground?

PLS HELP

Answer 1

She stone hit ground 42.86 m far from base of cliff.

Step-by-step explanation:

Initial height from ground = 40 meter.

We have equation of motion ,
`s= ut+(1)/(2) at^2`, s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

In this the velocity of body in vertical direction = 0 m/s, acceleration = 9.8
`m/s^2`, we need to calculate time when s = 40 meter.

Substituting

`40=0*t+(1)/(2) *9.8*t^2\\ \\ t = 2.86 seconds`

So it will take 2.86 seconds to reach ground.

So, stone travels horizontally at 15 m/s for 2.86 seconds.

Distance travelled = 15 x 2.86 = 42.86 m

So, the stone hit ground 42.86 m far from base of cliff.