Question

A stone is thrown in a vertically
and direction with a velocity
5 ms-1. If the acceleration of the
stone during its motion is 10ms-2
in the downward direction, what
will be the height attained by the
stone and how much time will it
take to reach there?​

Answer 1

Correct Question:-

A stone is thrown in a verticaly upward direction with a velocity of 5m/s.If the acceleration of the stone during it's motion is 10 m/s² in the downward direction,what will be the height attained by the stone and how much time will it take to reach there?

Given:-

• Initial velocity (u) = 5 m/s

• acceleration (a) = -10 m/s² (because of Gravitational force)

• Final velocity (v) = 0 m/s

To Find:-

• Required height = ?

• Required time = ?

Solution:-

$\tt\boxed\star\purple{\underline{\underline{{Using\:third\:equation\:of\: motion:-}}}}$

We know that,

$\pink{\boxed{\bf{{v}^{2}={u}^{2}+2as}}}$

$\rm\implies\:{0}^{2}={5}^{2}+2\times\:(-10)\times\:s$

$\rm\implies\:{0}^{2}=25+(-20)s$

$\rm\implies\:20s=25$

$\rm\implies\:s=\dfrac{25}{20}$

$\rm\implies\:s=1.25\:m$

hence, the required hight will be 1.25 m.

Now,

$\tt\boxed\star\green{\underline{\underline{{Using\:first\:equation\:of\:motion:-}}}}$

$\red{\boxed{\bf{v=u+at}}}$

$\rm\implies\:0=5+(-10)t$

$\rm\implies\:10t=5$

$\rm\implies\:t=\dfrac{5}{10}$

$\rm\implies\:t=0.5\:sec$

hence, required time will be 0.5 sec.