Question

a stone is dropped from the top of a tower of height 100 M the stone penetrates in the sand on the ground through distance of 2 m calculate the retardation of the stone

Answer 1

Answer: The retardation will be $490\ m/s^2$

Explanation:

Given that,

Height h = 100 m

Distance d = 2 m

Using kinetic and potential energy

Kinetic energy = Potential energy

$\dfrac{1}{2}mv^2= mgh$

$\dfrac{1}{2}v^2= 9.8\times100$

$v= 44.3 m/s$

When the stone penetrates in the sand on the ground through distance of 2 m then,

The retardation will be

Using equation of motion

$v^2-u^2=2ah$

$0-(44.3)^2=2\times a\times2$

$a = -\dfrac{(44.3)^2}{4}$

$a = -490\ m/s^2$

Hence, The retardation will be $490\ m/s^2$