Question

stone is dropped from a height of 20metre how long will it take to hite the group.(g m/s)​

Answer 1

Question :

A stone is dropped from a height of 20metre .How long will it take to hit the ground.(g = 9.8m/s^2)

Given :

initial Velocity, U = 0

initial Velocity, U = 0Height , h = 20 metre

initial Velocity, U = 0Height , h = 20 metreacceleration, g = 10 m/s^2

To Find :

Time taken to hit the ground

Solution :

Using second equation :

$\bf \blue{\boxed{s =ut + \frac{1}{2}a {t}^{2}}}$

$\implies \: 20 = 0 \times t + \frac{1}{2} \times 10+ {t}^{2}$

$\implies \: 20 = 0 + 5 {t}^{2}$

$\implies {t}^{2} = \frac{20}{5}$

$\implies \: {t}^{2} = 4 \implies \: t \: = \sqrt{4}$

$t \: = 2$

So the time taken to hit the ground is

$\bf \small \purple{ \boxed{ \boxed{t = 2 \: sec}}}$