If a car has a constant acceleration of 4 m/s ^ 2 starting from rest, how fast is it traveling after 5 seconds ?

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)