Question

A rock is dropped from rest from a height above a strange planet, and a strobe-light photograph is taken. The image is damaged in transmission to earth so that an unknown part of the top of the picture is lost. However, five successive images of the falling rock can be seen. The spacing between the remaining images corresponds to 3.1570 m, 3.2390 m, 3.3210 m, and 3.4030 m, and the flash rate is 10.0 flashes per second. Calculate the acceleration of gravity on that planet ( m/s2).