Question

A soccer ball is kicked with an initial speed of 8.8 m/s. After 0.179 s it is at its highest point. What was its initial direction of motion?

Answer 1

Answer is in degrees (above the horizon)

Answer 2

we just need the verticle component to find the angle using inverse sine.
\[V=V1 + A*T\]
V1 = unknown
V(at highest point) = 0
A= gravity = -9.8 m/s^2
T=.179s
\[0=V1 - 9.8m/s^2 * 0.179s\]
V1=1.7542m/s
\[\sin \Theta = (1.7542m/s) / (8.8m/s)\]
use inverse of sine to leave theta on the left alone
\[\Theta =\sin^{-1} (1.75/8.8)\]
\[\Theta = 11.50 degrees\]