Initial Velocity
From our original data, we know the horizontal displacement of the ball, and the time from contact to when it hit the ground. From our pictures, we know that the ball was hit at an angle of 18º (see Data Collection) Since we have the displacement of the ball and the time from when the ball left the racquet to when it bounced, we can determine the horizontal velocity of the ball. We can then use trigonometry and Pythagorean theorem to determine the initial vertical component and the actual initial velocity:
Therefore the horizontal velocity is 16.5m/s [FWD]
Therefore the initial vertical velocity is 5.36m/s [UP]
Therefore the actual initial velocity is 17.3m/s [18º above the horizontal]
Therefore the initial vertical velocity is 5.36m/s [UP]
Therefore the actual initial velocity is 17.3m/s [18º above the horizontal]
Final Velocity
Once we have this information, we can solve for the final vertical velocity using our acceleration equation, and then finally, we can find the angle at which the ball hits the ground using trigonometry:
Therefore the final vertical velocity is 6.6m/s [DWN]
Therefore the ball hits the ground at an angle of 22º below the horizontal