Question

An astronaut on a planet with no atmosphere drops a feather into a 5.90m deep crater and records that the feather falls freely for 1.64s.

What is the magnitude of free-fall acceleration on the planet?

With what speed does the feather strike the bottom of the crater?

Answer 1

a) $h=gt^2/2\to g=2h/t^2=2\cdot5.9/1.64^2=4.39(m/s^2)$

b) $v=gt=4.39\cdot1.64=7.2(m/s)$