An astronaut is on a new planet. She discovers that is she drops a space rock from 12m above the groundnut has a final velocity of 3m/s just before it strikes the planet surface. What is the acceleration due to gravity on the planet?

-0.375 m/s2

Explanation:

To find the acceleration due to gravity in this planet, we can use the Torricelli formula of UALM (uniformly accelerated linear motion):

V^2 = Vo^2 + 2*a*S

Where V is the final velocity, Vo is the inicial velocity, a is the acceleration and S is the total displacement.

With V = 3, Vo = 0 and S = - 12, we have:

3^2 = 0^2 - 2*a*12

24a = - 9

a = - 9/24 = - 0.375 m/s2