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Explore the effects of drag and wind on projectile motion, including how air density and wind influence trajectory. Use a 3D cannon model in Java to analyze the results.
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Projectile Motion By: Sam, Jacob, and Wendell
Outline • Drag (air resistance) • How does air density affect trajectory • How does wind affect affect trajectory • Model of a cannon in 3 dimensions (java)
Recap • Shoot a projectile at a target • Time step is .01 seconds • Optimal angle 45°
How drag works • Drag = cd * r * V2/2 * A • Drag coefficient (cd) is a constant on earth • Density of the air ( r ) changes with altitude • Velocity of the cannon ball (V2) starts between 400 and 500 m/s • Surface area of the cannon ball (A) is 0.04524 m2
3D plot • Added Z axis • Used two graphs to get 3D • Wind in two directions • New angle (Z) Y,X X,Z
Density change Higher altitude less density No change in density
Wind • No wind on the Y axis • Wind factors into drag
No wind • + wind increases drag • no wind gives the • - pushes the ball ball a natural path a graph with no wind
Results • Wind has little effect on trajectory of a cannon ball • Density change can make a cannon ball go farther • Adding the Z axis made it much harder to hit the target
References • http://www.grc.nasa.gov/WWW/K-12/airplane/falling.html • http://www.nps.gov/fomc/archeology/cannon.jpg • http://orgs.unt.edu/talons/rush/cannon.jpg