(b) an example of an inverse square field is the gravitational field f = −(mmg)r/|r|3. use part (a) to find the work done by the gravitational field when the earth moves from aphelion (at a maximum distance of 1.52 108 km from the sun) to perihelion (at a minimum distance of 1.47 108 km). use the values m = 5.97 1024 kg, m = 1.99 1030 kg, and g = 6.67 ✕ 10−11 n·m2/kg2. (round your answer to two decimal places.)