Q. Your motorboat can move at 30km/h in still water. How much time would it take you to move 12km upstream, in a river flowing at 6km/h?
Q. (a) Find out the speed of a satellite moving around the earth in a circular orbit that has a radius equal to six times the earth's radius of 6.38 x10^6 m.
(b) Find out the satellite's orbital period.