- #1
skiing4free
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Homework Statement
What is the Kinetic energy of a 180-kg satellite which circles the Earth (radius=6.4x10^6m, mass=6.0x10^24kg) with a period of 8.0 h?
a)2.2x10^9J
b)2.0x10^9J
c)1.8x10^9J
d)2.4x10^9J
e)3.6x10^9J
Homework Equations
Ep= GM1M2/r
Ek=.5Mv^2
Ac=(4[tex]\pi[/tex]^2r)/T^2
v=-[tex]\omega[/tex]^2r
Ep=Ek
The Attempt at a Solution
The radius that the satellite is orbiting is not given only Earth's radius, i tried to use ratios but this cannot work as the satellite is moving much faster than earth. Then i tried a guess and check method with the given options trying to cross check the speed. Eventually i got an answer of 1.8x10^9J which is correct. There must be a better method for calculating the radius of the satellite?