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## Homework Statement

A space traveller lands on a small planet whose circumference is 12,500 km. He releases a hammer and a table tennis ball simultaneously from rest and from a height of 1.6 m, timing their fall to take 0.66 s. Determine the density of the planet. What can you conclude about its atmosphere?

## Homework Equations

[itex]x = \frac{1}{2} \gamma t^2[/itex]

[itex]V

_{sphere}=\frac{4}{3} \π r

^{3}[/itex]

Circumference = [itex]2 \pi r[/itex]

## The Attempt at a Solution

[itex]r = \frac{12,500}{2 \pi } = 1989 km[/itex]

[itex]V

_{sphere}= \frac{4}{3} \pi r

^{3}= 3.30*10

^{10}km

^{3}[/itex]

[itex] \gamma = \frac{2x}{t^2} = \frac{3.2}{0.66^2} = 7.35 m.s

^{-2}[/itex]

Since the density [itex]ρ=m/V[/itex], is there a way to determine the mass of the planet with the acceleration due to gravity, to then figure out the density with the formula?

Thanks for the help !

Also...a bit of help with LaTeX please !!