A ball is fired at a speed of 8 m/s at 20˚ above the horizontal from the top of a 5 m high wall. How far from the base of the ball will the ball hit the ground? Also calculate the angle below horizontal the velocity vector makes.

Answer 1

time in air:
hf=hi+vi*t-1/2 (9.8)t^2
0=5+8sin20*t-4.9t^2
solve that quadratic, use the quadratic equation.

Now, distance from base:
d=8Cos20*timeinair.

the angle: at impact?
arctan(verticalveloicty/horizontal)
verticalvelocity..
vf=8sin20-9.8t^2
so
angle arctan(vf/8cos20)