surface, where R is the value of the mean radius of the earth. If the gravitational satellite of mass 66 kg is in orbit round the earth at a distance of 5-7R above its field strength at the earth's surface is 98 N kg, calculate the centripetal force acting Assuming the earth's mean radius to be 6400 km, calculate the period of the on the satellite. satellite in orbit in hours. (L.) 19 (a) Explain what