The balloon will accelerate upwards relative to the planet. The lift accelerates downwards relative to the planet. The person accel;erates down at the same rate as the lift and stays standing on teh floor of teh lift. The balloon goes up and wedges in the lift roof so it subsequently accelerates down (unless huge balloon capable of dragging lift up). Acceleration of balloon -lift-person system oncwe the balloon wedges is slightly less than “g” due to upthruast of balloon. What is the subtlety of the problem?