# Radius of Mercury (celestial body) !

1. Jul 24, 2014

### new hand

1. The problem statement, all variables and given/known data
It is given that the period of Mercury is 87.9 days and the angular speed of Mercury is 8.27*10^-7
I have no idea how to calculate the radius just the two pieces of information given. Should there also be the linear velocity of Mercury given in order to calculate the radius??

2. Relevant equations
v= r ω
ω= 2∏/T
a= v^2/r or a= r ω^2

Any help would be greatly appreciated. Thank you!

Last edited: Jul 24, 2014
2. Jul 24, 2014

### CWatters

Deleted.

3. Jul 24, 2014

### Bandersnatch

You of course mean the radius of the orbit, not of the planet.

It does seem like the question is not giving you enough data to calculate the radius using the equations provided.

However, you may be able to obtain the radius using even less information that is given(i.e., just the period). Try applying Kepler's 3rd law of planetary motion.