posted by Chanel on .
3. It’s fourth down in the big football game, and the game is tied with 2 seconds to go! You are called on to win the game with the biggest field goal of your life, from 36 meters. The crowd holds its collective breath as the ball is spotted, and you kick it. It leaves your foot with a speed of 22 m/s at an angle of 52º above the ground. The crossbar on the goal post is 3.05 meters high.
A. How long does the ball take to reach the goal post? (5 points)
B. What is the ball’s speed when it reaches the goal post? (5 points)
C. By how much is the ball above or below the crossbar when it reaches the plane of the goal post? (5 points)
in the x-direction,
vx = 22*cos52º = 13.5m/s
it travels 36m in 36/13.54 = 2.66 seconds
neglecting air resistance
vy = 22*sin52º - 9.8t = 17.34 - 9.8*2.66 = -8.73
vx is still 13.54
use pythagorean theorem to add the vectors
y = 0 + 17.34t - 4.9t^2 = 17.34*2.66 - 4.9*2.66^2 = 11.45
so, it clears the bar