A ball is thrown horizontally from the top of

Question

a building 45.2 m high. The ball strikes the
ground at a point 78.9 m from the base of the
building.
The acceleration of gravity is 9.8 m/s
2
.
Find the time the ball is in motion, initial velocity, and x and y components

Answer 1

the height y is

y = 45.2 - 4.9t^2
solve for t when y=0

using that t, since the horizontal velocity v does not change,

vt = 78.9