Question

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?

Answer 1

Given: Time (t) = 5 s, height (s) = 5 m

To find: Gravitational acceleration (g)

Formula: s = ut + `1/2 "gt"^2`

Calculation: From formula,

5 = `0 xx 5 + 1/2 "g"(5)^2`

∴ `5 = 1/2 "g" xx 25`

∴ g = `2/5`

∴ g = 0.4 m/s² 

The gravitational acceleration of the planet is 0.4 m/s².