Question

A 40-kg rock is dropped from an elevation of 10 m. What is the velocity of the rock when it is 5-m from the ground?

Answer 1

Step-by-step explanation:

Given

mass of rock
`m=40\ kg`

Elevation of Rock
`h=10\ m`

Distance traveled by rock with time

`h=ut+(1)/(2)at^2`

where, u=initial velocity

t=time

a=acceleration

here initial velocity is zero

when rock is 5 m from ground then it has traveled a distance of 5 m from top because total height is 10 m

`5=0* t+(1)/(2)(9.8)(t^2)`

`t^2=(10)/(9.8)`

`t=1.004\approx 1\ s`

velocity at this time

`v=u+at`

`v=0+9.8* 1.004`

`v=9.83\ m/s`