Q.
The period of revolution of planet A around the sun is 8 times that of B. The distance of A from the sun is how many times greater than that of B from the sun?
Period of revolution of planet A(TA)=8TB.
According to Kepler's III law of planetary motion T2∝R3.
Therefore (rBrA)3=(TBTA)2=(TB8TB)2=64
or rBrA=4
or rA=4rB.