Question

a. 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?

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Answer 1

$\mathfrak{Solution:-}$

g is the acceleration in the body due to its gravity. Since, gravity of a planet produces constant acceleration in the body we can use the three kinematic equations.

Assuming the body was dropped, i.e. the initial velocity is zero

$\sf{using\; S=ut+(1/2)at^{2}}$

Where,

$\sf{S=displacement=5m}$

$\sf{u=initial\;velocity=0}$

$\sf{a=acceleration=g}$

$\sf{t=time=5s}$

$\sf{S=ut+(1/2)at^{2}}$

$\sf{5=(1/2)g(5)^{2}}$

$\sf{g=2/5}$

$\sf{=0.4\;m/s^{2}}$