- #1
pinkybear
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Homework Statement
A spherical asteroid has a density of 2600 kg/m^3. I throw a ball at the speed on 20 m/s. If the ball is to travel in a circular orbit, what is the largest radius of the asteroid possible to accomplish this?
Homework Equations
these are the equations I used..
escape velocity:
V(e)=sqrt(2GMm/r)
and
Density:
mass=Volume*Density
volume= 4/3(pi)r^3 (since the asteroid is spherical)
GM= 6.67*10^-11 (constant)
The Attempt at a Solution
m=4/3 pi r^3*2600
20^2=[2(6.7*10^-11)(4/3 pi r^3*2600)]/r
or simplified:
400=(1.453*10^-6)*r^2
or
r= 16593 or 17000 (2 s.f)
My answer is wrong.. I have 4 tries left. I'm thinking that I messed up on the GM(gravitational force) part, but I don't know how or why. Is it correct to use the constant?