A car drives straight off the edge of a cliff that is 58 m high. The police at the scene of the accident note that the point of impact is 126 m from the base of the cliff. How fast was the car traveling when it went over the cliff?
Calculate the time that it takes to fall 58 m. It will not depend upon the car's velocity, just the cliff height.
Divide 126 m by the time it takes to fall to the base of the cliff.
That wll be the car's velocity when it leaves the cliff. That velocity remains the horizontal component of V as it falls.