Question

One way to measure g on another planet or moon by remote sensing is to measure how long it takes an object to fall a given distance. A lander vehicle on a distant planet records the fact that it takes 3.17 s for a ball to fall freely 11.26 m, starting from rest. What is the acceleration due to gravity on that planet?

Answer 1

11.26 m = 1/2 * g * (3.17 s)^2

Answer 2

x = 1/2 a t^2 ==> a = (2x) / t^2
a = 2(11.26m) / (3.17s)^2
a = 22.52m / 10.0489s^2 = 2.241041308 ==> sig figs
a = 2.24m/s^2