Question
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.
Answers
bobpursley
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)
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)