In: Physics
A soccer player kicks the ball toward a goal that is 27.6 m in front of him. The ball leaves his foot at a speed of 18.5 m/s and an angle of 31.2° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not 18.5 m/s.)
I keep getting a final velocity of 13.92797m/s but its incorrect. Please show your work so I can see what I'm doing wrong.
Initial velocity of the ball,
Initial vertical velocity,
Initial horizontal velocity,
Distance to goal,
===================
First, find the time of flight
Consider the horizontal motion of the ball
There is no acceleration in the horizontal direction, so horizontal velocity remains a constant
Horizontal velocity = Horizontal Distance/Time of flight
============================
Consider the vertical motion of the ball
Use formula
Initially, the ball is going up and g is acting downwards, so put a negative sign for g
Note: Negative sign just indicates that the ball is falling
====================
Consider the horizontal motion of the ball
There is no acceleration in the horizontal direction, so horizontal velocity remains a constant
------
Final velocity,
ANSWER :
============================