Answer:
[tex]v = 4.47 \times 10^3 m/s[/tex]
Explanation:
As we know that time period is given by the equation
[tex]T = 2\pi \sqrt{\frac{r^3}{GM}}[/tex]
so we know that
[tex]r = 20,000 km = 2\times 10^7 m[/tex]
[tex]M = 6 \times 10^{24} kg[/tex]
here we have
[tex]T = 2\pi\sqrt{\frac{(2 \times 10^7)^3}{(6.67 \times 10^{-11})(6 \times 10^{24})}}[/tex]
[tex]T = 2.81 \times 10^4 s[/tex]
now in order to find the speed we can say
[tex]speed = \frac{distance}{time}[/tex]
[tex]speed = \frac{2\pi r}{T}[/tex]
[tex]v = \frac{2\pi(2 \times 10^7)}{2.81 \times 10^4}[/tex]
[tex]v = 4.47 \times 10^3 m/s[/tex]
