The first artificial satellite to orbit the earth was sputnik i, launched october 4, 1957. the mass of sputnik i was 83.5 kg, and its distances from the center of the earth at apogee and perigee were

The first artificial satellite to orbit the earth was sputnik i, launched october 4, 1957. the mass of sputnik i was 83.5 kg, and its distances from the center of the earth at apogee and perigee were approximately 7290 km and 6570 km, respectively. find the difference in gravitational potential energy for sputnik i as it moved from apogee to perigee. (use a positive sign for an increase, negative sign for a decrease in u.)