Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 310 kg. The balloon is motionless in the air, because the downward-acting weight of the people and balloon is balanced by an upward-acting “buoyant” force. If the buoyant force remains constant, how much mass should be dropped overboard so the balloon acquires an upward acceleration of 0.15 m/s2?

1 answer

The decrease in weight equals the new net accelerating force.

(Dropped mass)* g = M a

Solve for the dropped mass.

The acceleration will not continue forever.. Eventually aerodynamic drag limits the speed.