Question

From the top of a tower of hieght 490m a boy throws a stone horizontally with initial speed 15 find the speed with which the stone hits the ground

Answer 1

The speed of stone when it hits the ground is 99.14 m/s

Explanation

Given,

The height of the tower (s) = 490 m

initial speed of the stone (u) = 15 m/s

Formula for final velocity in this case = v²₋ u² = 2as

v is the final speed, so we transform this equation.

V = $\sqrt{2as + u^2}$

Here in this case acceleration (a) becomes gravitational constant (g) because it is a freely falling body.

gravitational constant (g) = 9.8 m/s²

V = $\sqrt{2ag + u^2}$

V =  $\sqrt{2 (9.8) (490) + (15)^2}$

V = $\sqrt{9604 + 225}$

V = $\sqrt{9829}$

V = 99.14 m/s

final speed when stone hit the ground = 99.14 m/s