The equation d = 16t

2 gives the distance d in feet that a golf ball falls in t seconds. How many seconds will it take a golf ball to drop to the ground from a height of 4 feet? 64 feet?

It will take a golf ball seconds to drop to the ground from a height of 4 feet.

It will take a golf ball seconds to drop to the ground from a height of 64 feet.
Someone please help I dont get it and the time is limited! :(