## Essential University Physics: Volume 1 (3rd Edition)

We know that the current radius of orbit is equal to its height plus the radius of the earth. Thus, we find: $r=(6.37\times10^6)+(5.5\times10^6)=1.187\times10^7$ a) We know that the orbit changes by a factor of $1-\frac{1}{1.1^2}=.17$ We multiply this by the value of r to find: $r=\fbox{2,060,082 meters}$ b) In this problem, we need to use the equation for orbital period to find the change in radius. Since the value of T is squared and the value of r is cubed, we find that the orbit changes by a factor of $|1-\frac{1}{.9^{2/3}}|=.06783$ We multiply this by the value of r to find: $r=\fbox{805,145 meters}$