Part 1: Find the initial speed of the ball leaving the projectile launcher.

Fire the ball straight up into the air and measure it's maximum height three times.

1. Heights and average

distance 1  
distance 2  
distance 3  
average distance  

2. In the box below, draw a picture showing the motion of the ball and then calculate the ball's initial speed using: v = ã(20dav
(Since v2 = 0, this comes from:    a = (v2 - v1)/t = -v1/t => t = -v1/a = v1/10, and
                                                        vav = 1/2(v1+v2) = v1/2, and
                                                        d = vavt = v1t/2 = v12 /20 => v1=ã(20d)  )






Part 2: Measure distances the ball goes at different angles.

3. Distances and angles

 angle distance

4. Plot the distances on a graph, using a ruler-drawn scale.









5. Use the graphing program LoggerPro to graph the distance and angle data. Find the best "curve fit" for the data using the "polynomial function" option. Print out the graph with the curve fit on it.

6. From the graphs, what is the estimate of the angle at which the ball would go the greatest distance?



7. Why is the angle for maximum range NOT 45‹?