Question

The acceleration due to gravity on or near the surface of Earth is 32 ft./s/s. Neglecting friction, from what height must a stone be dropped on Earth to strike the ground with a velocity of 136 ft./s

Answer 1

Given :

The acceleration due to gravity on or near the surface of Earth is 32 ft/s/s

To Find :

From what height must a stone be dropped on Earth to strike the ground with a velocity of 136 ft/s.

Solution :

Initial velocity of stone, u = 0 ft/s.

Now, by equation of motion :

$2as = v^2 -u^2 \\\\2\times 32 \times s = 136^2 -0^2\\\\s = \dfrac{136^2}{2\times 32}\ ft\\\\s = 289 \ ft$

Therefore, height from which stone is thrown is 289 ft.