An object takes 5 s to reach the ground from a height of 5 m on a planet. What is the value of g on the planet?

The given in the question can be listed as 

time t = 5s

height h = 5m

initial velocity u = 0m/s

To find , g =?

Solution - 

Using the formula 

g = ( 5x2) / 25 = 10/25 

g = 0.4 m/s²