1. The problem statement, all variables and given/known data A hot-air balloon consists of a basket, one passenger, and some cargo. Let the total mass be M. Even though there is an upward lift force on the balloon, the balloon is initially accelerating downward at a rate of g/3. The passenger notices that he is heading straight for a waterfall and decides he needs to go up. What fraction of the total weight must he drop overboard so that the balloon accelerates upward at a rate of g/2? Assume that the upward lift force remains the same. Lift Force = 2Mg/3 2. Relevant equations F = ma 3. The attempt at a solution I basically just tried to divide 2Mg/3 with g/2. But I just got M(4/3). The answer is 5/9. What critical information am I missing?