lab+3-+cannon+lab


 * Lab 3: Cannon Lab**


 * Primary Authors:** Amanda, Anna, Alli


 * Contributing Authors:**


 * Abstract:** The goal of this lab was to find the final velocity of a tennis ball after it explodes out of a cannon.


 * Introduction:** The lab was set up by taking a cannon and plunging it to introduce oxygen to encourage an explosion. Then lighter fluid was added to a hold in the cannon after a tennis ball was firmly placed inside. The ball and the cannon were moved around to encourage the evaporation of the fluid because the vapors of lighter fluid are extremely flammable. Once there were vapors present, the cannon was set down and a lighter was placed near the hole until ignition took place, launching the ball very quickly out of the end of the cannon, which was pointed parallel to the ground down a long, clear hallway.


 * Methods:** A tennis ball was placed into a cannon, then fired by the ignition of the cannon. A photogate was used to determine the time. Photogates have a light running throught them that are motion activated. When an object passes throught the stream of light the gate is open, and timing begins. Then when the object is no longer in the path of the light, it is closed, and timing stops.


 * Results:**

Mass of Ball= 0.057kg Mass of Cannon= 1.276kg Flag length on Cannon= 5cm
 * ~ Trial ||~ Time (s) ||~ V of Cannon (m/s) ||~ V of Ball (m/s) ||
 * 1 || 0.022 || 2.27 || 50.877 ||
 * 2* || 0.002 || 25 || 559.649 ||
 * 3 || 0.0174 || 2.87 || 64.328 ||
 * Data is inaccurate due to the Photo Gate being knocked over by the Cannon

Length of Flag (.05 m) / Time through PhotoGate x Mass of cannon (1.276 kg) / Mass of ball (.057 kg) = Velocity of ball
 * Calculations:**

Since the change in momentum is given by the equation P=mv, the mass of the cannon was known and so was the data necessary to find its final velocity. This was found by dividing the distance it went (.05 m) by the time it took to go that far. This gave the velocity in m/s. Then this was multiplied by the mass of the cannon to give the momentum. Since the change in momentum of one object equals the change in momentum of another, the momentum was known and so was the mass of the ball, dividing the momentum by that mass (.057 kg) gave the velocity in m/s.

..................... time 100
 * V of Cannon=** __5cm__ x __1__

M of ball X V of ball = -M of cannon X V of Cannon
 * V of Ball: __/\__ P of ball = -__/\__ P of Cannon**

V of Cannon= __0.057 X V of ball__ ........................-1.276

Diagrams:


 * Conclusion:** The speed of the tennis ball was found to be extremely fast, the top accurately recorded speed being 64.328 m/s, which is about 144 mph. This is because the explosion inside the cannon produced enough pressure to launch the ball forward significantly faster than the cannon because the mass of the cannon was about 22 times the mass of the tennis ball. It can be concluded that when two objects have the same momentum but one has more mass, it follows that the heavier object will have a slower velocity to offset the discrepancy in one aspect of the equation.