# Physics

posted by
**James**
.

The escape speed from a planet of mass 2.5×10^24 is 7.0 km/s.What is the planet's radius?

Iam using the formula v=sqr(2GM/r)

v=7

G=6.67*10^-11

M=2.5*10^24

r=?

I get 6.8*10^12

Where did I go wrong?