A soccer player kicks the ball toward a goal that is 16,8m in front of him . The ball leaves his foot at a speed of 16,0m/s and an angle 28,0degree above the ground.Find the speed of the ball when the goalie catches it in front of the net?

Answer 1

ah --- if the altitude of the kicking foot and the goalie hands is the same, then the kinetic energy is the same.
same (1/2) m v^2
so same 16 m/s

(ignoring air friction)

Answer 2

vx stays constant at 16cos28
time to goal = 16.8/16cos28
vy at goal = = 16.8sin28(t)- 1/2gt^2
Then Pythagoean with vx and vy