An elevator is rising at a constant speed. what forces are acting on the elevator? a. gravity b. air resistance c. gravity and air resistance d. gravity, air resistance, and normal force

Ahot-air balloon takes off from the ground traveling vertically with a constant upward acceleration of magnitude g/4. after time interval δt, a crew member releases a ballast sandbag from the basket attached to the balloon. how many seconds does it take the sandbag to reach the ground? (express your answer in terms of δt)