# Problem 4-21-Projectile

A football is placed on a line $25\; m$ from the goalpost. The placement kicker kicks the ball directly toward the goalpost, giving it a velocity of $21.0\; m/s$ at an angle of $47.0^\circ$ above the horizontal. The horizontal bar of the goalpost is $3.0\; m$ above the field. How far above or below the horizontal bar of the goalpost will the ball travel?

We must choose a coordinate system in which to solve the problem. Which is best?

(A)

(B)

(C)

(D)