When a parachutist jumps from an airplane, the distances, in feet, that the parachutist falls in each

Question:

When a parachutist jumps from an airplane, the distances, in feet, that the parachutist falls in each successive second before pulling the ripcord to release the parachute are as follows:
16, 48, 80, 112, 144, c.
Is this sequence arithmetic? What is the common difference? What is the total distance fallen in 10 sec?