Does anyone know the answer for this?

How long would it take for a ball dropped from the top of a 576-foot building to hit the ground? round your answer to two decimal places.

6n^2-7n-75=0 solve by quadratic formula

Aman steps out of a plane at a height of 4,000m above the ground falls 2,000m very quickly and then opens his parachute and slowly falls the remaining 2000m to the ground what height above the ground would be the best choice for a reference point