Masses My and m² are initially separated by a distance Ra. Mass m² is now moved further away from mass Mj such that their final separation is Rb. Which of the following statements best describes the work Wab done by the force of gravity on m² as it moves from Ra to Rb?
1) The work done is positive
2) The work done is negative
3) The work done is zero
4) The work done cannot be determined without additional information