If a light ray enters a 6m corridor at an angle of 45 degrees, where would we place the mirror to get the light ray to make it out of the corridor.

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)