Softball Toss – aka “Where have you gone, Jennie Finch?”

Objectives: Utilize your knowledge of kinematics, vectors, and projectile motion to analyze the trajectory of a softball. Using time, distance, “g”, and vector analysis, determine the velocity of a softball thrown into air.

Materials: softball, stopwatch/cell phone w/timer, open area/field, metersticks or tape measure

NOTES: Each “team” has 1 thrower, 2 timers/spotters

*disregard air resistance in all calculations

Methods:

1)  Prepare a data table to record your group’s throw. Include the:
A. total time in the air measured to 0.1 seconds based on an average time of the two timers (from moment the ball is released until the moment the ball lands).
B. horizontal distance the ball travels measured to 0.1 meter (the throw must be perpendicular to the starting line)

2)  Throw the softball underhand 10 - 20 m high to maximize "hang time." Use a high angle of throw. Hang time is more important than range.

3)  Each group only needs one successful trial. However, both timers must be within 0.1 seconds of one another, so continue to perform trials until an appropriate degree of precision is reached with minimal uncertainty.

Analysis of your throw:

1)  Showing all work and using the kinematics equations and your data for time and distance, determine vf,x and vf,y - the vertical and horizontal velocities just before impact with the ground, AND the maximum height of the ball.

2)  Using graphical vector analysis (i.e., a ruler and a protractor), draw to scale vi,x and vi,y - the initial vertical and horizontal velocity components. The total velocity and angle that you threw the ball is represented by the resultant vector. For your throw, graphically determine the resultant release velocity and the angle of throw above the horizontal. *Remember that final velocity is equal to initial velocity but with the opposite sign.

3)  In the absence of air resistance, predict & explain the ideal angle to maximize horizontal distance. Support your answer mathematically.

4)  Showing all work as necessary (some parts may not require calculations), mathematically determine the following for your throw:
a) “g” at the maximum height of the throw
b) the resultant velocity of the ball just prior to impact.
c) the vertical and horizontal velocities at the top of the parabolic flight.

5)  In one paragraph, write a detailed individual summary and conclusion/evaluation to the lab. Discuss not only your results, but also systematic error with direction, random error, improvements or modifications, etc.