You are at a distance of `R = 1.5xx10^(6)` m from the centre of an unknown planet. You notice that if you throw a ball horizontally it goes completely around the planet hitting you in the back 90,000 seconds later with exactly the same speed that you originally threw it. If the length of semi major axis of ball is 2R, what is the of the planet. Express in form `axx10^(b)` kg and fill a+b in OMR sheet.
`["Take" : G = (20)/(3)xx10^(-11)Nm^(2)//kg^(2), pi^(2)=10]`

Answer

23

Explanation

`T = (2pi(a)^(3//2))/(sqrt(GM))` so `M = (4pi^(2)(a)^(3))/(GT^(2))`
Putting values we get
`M =2xx10^(21)kg`