 
Arturo O. answered  12/02/19
Experienced Physics Teacher for Physics Tutoring
Use Kepler's 3rd law.
T = period
R = orbital radius
R3/T2 = constant
RA3 / TA2 = RB3 / TB2
TB = 8TA ⇒
RB3 = (TB / TA)2 RA3 = 82 RA3
RB = (64)1/3 RA = 4RA = 4R
 
        Sarah B.
asked  12/01/19Satellite B has mass m and orbits a planet of mass M. What should satellite B's orbital radius be so that its period is 8 times that of satellite A?
(The answer is 4 R I just don't know how to get there)
 
Arturo O. answered  12/02/19
Experienced Physics Teacher for Physics Tutoring
Use Kepler's 3rd law.
T = period
R = orbital radius
R3/T2 = constant
RA3 / TA2 = RB3 / TB2
TB = 8TA ⇒
RB3 = (TB / TA)2 RA3 = 82 RA3
RB = (64)1/3 RA = 4RA = 4R
 
        
                Get a free answer to a quick problem.
                Most questions answered within 4 hours.
            
Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.
Arturo O.
I want to add that Kepler's 3rd law applies here, since both A and B are orbiting a body of the same mass.12/02/19