A football kicker is attempting a field goal from $44 \mathrm {~m}$ out. The ball is kicked and just clears the lower bar with a time of flight of $2.9 \mathrm {~s}$ If the angle of the kick was 45°, what was the initial speed of the ball, assuming no air resistance?
A) 21.5 m/s
B) 19.7 m/s
C) 2.2 m/s
D) 39 m/s

Question

Quizplus · Accepted Answer

The horizontal distance $d$ is given by $d = v_0 \cos(\theta) \cdot t$. With $d = 44 \, \mathrm{m}$, $\theta = 45^\circ$, and $t = 2.9 \, \mathrm{s}$, solving for $v_0$ gives $v_0 = \frac{44}{\cos(45^\circ) \cdot 2.9} \approx 21.5 \, \mathrm{m/s}$.

A Football Kicker Is Attempting a Field Goal From 44 m44 \mathrm {~m}44 m

A Football Kicker Is Attempting a Field Goal From $44 \mathrm {~m}$