Several people are riding in a hot-air balloon. The combined mass of the people and balloon is 308 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 0.11 m/s2?

1 answer

WEll, the net force upward will be the weight of the mass dropped.
F=ma
mass*g=(308-mass)*acceleration

solve for mass dropped