# Projectile Motion

Simulation Used: Projectile Motion from the PhET at the University of Colorado.
• Initial settings:
• Set the initial vertical position of the cannon at the ground level

• Activity 1: Investigate how the firing range depends on the initial velocity.
• Make sure the Air Resistance box is unchecked. (Ignore Air resistance)
• Set the firing angle at 65o
• Perform the experiment:
• Choose an initial velocity vo equal to 16 m/s
• Fire a shot. Make sure the cannon is still positioned at ground level.
• In your notebook, write down the range and the time of flight.
• Repeat the procedure for initial velocities equal to 18 m/s, 20 m/s, 22 m/s, 24 m/s, 26 m/s, 28 m/s, and 30 m/s.
• In your lab notebook, write down the data in the following format:

 vo (m/s) vo2 (m/s)2 R (m) T (s) 16 18 20 22 24 26 28 30

• Results:
• Plot R vs. vo2. (Why do we plot R vs. vo2 and not R vs. vo?)
• Find the slope of the graph. You can use your calculator, spreadsheet, or you can go to this website. If you choose the latter, clear the data and type in your own data. The slope of the line is given by "m" in the box below the graph.
• Determine the gravitational acceleration g from the slope. Calculate the percent error, 100% . |gmeasured - 9.8|/(9.8)
• If this is a virtual simulations, why do you think there is an error in the value of "g"? Is it random?

Acknowledgements.
• The Java Applet comes from the PhET Interactive Simulations at the University of Colorado, Boulder.
• Partial funding for the creation of this lab manual was provided by the VCCS Paul Lee Professional Development Grant Program.