A stone is dropped from a height of 10 m on an unknown planet having g = 20 m/s2.

Question

Calculate the speed of the stone when it hits the surface of the planet. Also calculate the
time it takes to fall through this height

Answer 1

V^2 = Vo^2 + 2g*h = 0 + 40*10 = 400
V = 20 m/s.

0.5g*t^2 = 10 m.
10*t^2 = 10
t^2 = 1
t = 1 s.

Or
V = Vo + g*t = 20
V = 0 + 20t = 20
t = 1 s.