Question

a stone is projected vertically upwards with a speed of 30m/s from a height of 40m . Find the maximum height attained , the time required to strike the ground and the speed with which it strikes the ground​

Answer 1

Answer:

Hmax....40+45= 95 m

Explanation:

Answer 2

Explanation:

Given that,

Initial speed of the stone, u = 30 m/s

Final speed of the stone, v = 0

Acceleration due to gravity, $a=-9.8\ m/s^2$

Let h is the maximum height reached by the stone. It can be calculated using third equation of motion as :

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

$h=-\dfrac{u^2}{2a}$

$h=-\dfrac{(30)^2}{2\times (-9.8)}$

h = 45.91 meters

Let t us the time required to reach the ground,

$t=\dfrac{v-u}{a}$

$t=\dfrac{-30}{-10}$

t = 3 seconds

Hence, this is the required solution.