Answer:
-0.375 m/s2
Step-by-step 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