This project includes all the materials, steps, and math calculations needed to build your own marble cannon at home!
- 2 different sized PVC pipes cut to 30 centimeters in length (3/4 inch and 1/2 inch)
- electrical tape
- rubber bands
- 2 paper clips
- foam ear plugs
- super glue
- silicone spray
Step 1: Preparing the Pipes
Cut both PVC pipes to 30 centimeters in length. The pipe that is smaller in diameter (shown on the left) will be used as the plunger and the pipe that is larger (shown on the right) will be the pipe the marble shoots from. The plunger pipe should fit inside of the other pipe which should be large enough to hold a marble. Tape one end of the plunger pipe with electrical tape to give it an air tight seal.
Step 2: Sealing
Place the earplugs into the plunger pipe to seal it further. Super glue them into place to keep it airtight.
Step 3: Putting the Pipes Together
Apply the silicon spray to the inside of the larger pipe that will hold the marble. Put the plunger pipe into the larger pipe, be sure to turn it counter clockwise.
Step 4: Attaching Paper Clips and Rubber Bands
Use an unraveled paper clip and wrap it around the end of the larger pipe securely. Attach a regular paperclip on the unraveled one with a rubber band connected. On the other end of the rubber band, attach a second paper clip. This will be inserted into the end of the plunger when ready to fire the cannon.
Step 5: Firing the Cannon
Insert the marble into the larger pipe. Hold this pipe with one hand and pull back the plunger with the paper clip inserted. Release the plunger and the marble will fire.
Step 6: Projectile Motions Math
1) To calculate for the variables of projectile motion for your cannon, you must measure the angle at which you fired the marble as well as the distance it landed.
2) Refer to the provided equation to solve for how long the marble was in motion for.
- "t" is how long the marble was in the air
- "y" is the negative of the launching height, this should have remained the same for each trial
- "x" is the horizontal distance. This number should have varied.
-Theta is the angle at which the cannon was launched. This could have varied
- "g" is the force of gravity which is (-9.8)
3) Plug in the variables and solve for the time. Make sure centimeters are converted into meters.