Cannon Calibration Lab; Cannon #______

Name:______Date:______

Objective: Calculate how fast the cannonball leaves the cannon “Vx” for various cannon power settings, then use this calibration to fire at set targets.

Safety:

1) Must ware safety goggles

2) Never fire cannon without instructions

3) Cannon Must always be level before firing

Calculations:

Sample Calculations for Calibration: (5pts)

Your can is raised .65 meters off the ground and shoots a distance of 3.5 meters. How fast was your cannon moving upon leave the barrel:

Set-up Procedure:

1) Set cannon on stool and clamp down as shown in the locations specified by your instructor.

2) Mark a piece of tape at every corner of the stool (this is done so that the system may be accurately reset after each fire).

3) Make sure the cannon is level by using a level. If you bubble is not centered then place square papers under the front or back legs of the lab chair as shown.

4) From the tip of the barrel, place the plumb bob to indicate the location of the end of the barrel.

5) From the end of the plumb bob, place a measuring tape so that you may measure where the ball lands.

6) Yi; Measure the height of the cannon barrel to the ground. This is your height!!!

Yi = ______m remember 33cm =.33m

Calculate time to hit the ground:

Time = ______s (Record in Appendix A)

7) You are now ready to fire. We will all do this together!!!

Testing procedure:

1) Place the marble in the cannon and pull back the on the bow to the 5th notch. Then tip the gun slightly backwards (about 5º) so that the marble rests against the dowel rod. Slowly tip the gun to its original position

2) Launch the cannon and record its distance in the Table 1

3) Repeat 1 more time for each trial and then calculate the average distance.

4) When you are finished firing for power settings 5 -14.

5) Complete for the remaining notches.

Table 1 (5pts)

Notch # / Trial 1
Distance
D1 / Trial 2
Distance
D2 / Average Distance
Xf=(D1+D2)/2 / Time (s)
T = √(2*Yi/9.8) / Launch Velocity Vx
Vx = Xf/t
5
6
7
8
9
10
11
12
13
14

Calibration:On graph paper, plot very neatly (Notch # Vs. Vx) for notches 5 – 14. Label you axis (10 pts)

Ballistic Testing Site:

1) Go to the testing site to see how accurate you have calibrated your cannon. There will be a series of targets for you to hit. Choose a target and measure distance from the nozzle of the cannon to the target of your choice.

2) After gaining these measurements, calculate the initial velocity for your target as done in the beginning of this lab.

3) Go to your calibration chart and see what notch will yield that velocity.

4) Wait for instruction before loading and firing. If you hit point will be earned.

Target#:______Calcs: (Show all work) (5pts)