how do you solve this? with what formula?

Question

an astronaut has landed on a known planet. She drops a wrench from a height of 8.04 meters above the surface. The wrench takes 5.50 seconds to fall to the surface. What is the acceleration of gravity( in m/s2) on the planet?

Answer 1

Let's pick downwards as positive: a = g_p v₀ = 0 d = 8.04 m and t = 5.5 s

d = v₀t + (1/2)at² = (1/2)g_pt²

rearranging to solve for g_p:

g_p = 2d/t²

You should be good to go.