Question

A stone is dropped from height of 10 m on an unknown planet having G is equal to 20 metre per second square calculate the speed of the stone when it hits the surface of the planet also calculate the time it takes to fall through the the this site

Answer 1

40m/s, 20 seconds

Explanation:

The equation that we can use here is

$v^2 - u^2 = 2gS$

here v = final velocity of impact

u  = initila velocity = 0 since the stone is dropped without any initital velocity.

g = $20m/s^2$ on this particular planet

S = 20m = falling height

This gives us

$v^2 = 2*40*20$ = 1600

Square root both sides

v = 40m/s

Now, we also have the equation

$v = u + gt$

40 = 0 + 20t

This gives t = 2 seconds =