Mechanics

Cannon

Page 1

Experimental Instructions

Welcome to the ballistic simulator. Each new shot has a trajectory which is color coded. You get a maximum of 4 shots; when out of ammo press the more button.

This virtual experiment is designed to let the student measure the relation between muzzle velocity (which determines projectile energy), gravitational potential and the effects of frictional drag caused by wind speed blowing opposite to the direction the projectile is moving in.

Exercises to Try:

  1. Try to hit the target in 4 ties staring with the default settings and only changing the velocity (i.e. the kinetic energy)
  2. After you have successful hit the target double the gravity (i.e. raise it to -19.6). By what factor do you have to increase the velocity in order to now hit the target?
  3. Now set the windage slider to -14 units and turn drag on with the drag button. Compare the trajectory with and without the drag feature.
  4. Now, what do you suppose will happen if you lower the density of the projectile with the drag turned on?

This applet requires a Java enaled browser to function. If you are seeing this message, you are either not using a Java enabled browser, you have Java turned off, or the applet is broken. If you suspect the latter, please send a message to Sean Russell describing your problem. Please include which operating system, what kind of computer, and which web browser you were using when the problem occurred.

Here is your assignment:

The enemy band of tenured professors is approaching. Unfortunately you forget your handy supply of cannon balls and all you have is some textbooks and there is a 50 mile an hour head wind. The density of the textbooks is 0.55 (1/2 that of a cannon ball). Set the windage to -50, make sure drag is turn on and try to hit the target that represents the enemy band of tenured professors. Enlist the aid of an untenured professor to help. You have 4 shots, else the tenured professors will become "aware" (if that is possible) of the ballistic textbooks coming in their general direction.


Applet coding by Sean Russell
Graphic images by Amy Hulse
Content by Greg Bothun