1. The problem statement, all variables and given/known data The problem asks, "You lift a 10N book up in the air a distance of 1m at a constant velocity of 0.5m/s. The work done by gravity is: a. -10J b.-5J c. zero d. 5J e. 10J 2. Relevant equations W=FD Wg=mgh 3. The attempt at a solution So, the work done by whoever is lifting the book is 10J (W=FD) but with the hand still holding the book, is gravity doing work? I just really can't decide if gravity is doing "work" in this situation. Can someone point me in the right direction? Thank you!