Marshmallow Launcher A HandsOn Demonstration of the Bernoulli

Marshmallow Launcher A Hands-On Demonstration of the Bernoulli Principle Georgia CTAE Resource Network Instructional Resources Office Written by: Caleb Allred and Dr. Frank Flanders June 2009

Note This activity should be cleared with the school administration. The teacher should provide marshmallows to be used only under direct supervision.

Objective • The Bernoulli Principle is used to increase efficiency of a system. – for a flow, an increase in speed occurs simultaneously with a decrease in pressure.

Assignment Your assignment is to build a marshmallow launcher that will launch a marshmallow the greatest distance. This may also be used as an accuracy test (on the accuracy of the translation from the plan to the actual launcher) as well.

What You’ll Need • • • ½ inch PVC pipe ½ inch elbow fittings ½ inch T fittings ½ inch cap fittings Small marshmallows NO GLUE!!

Specifications • Student will receive 48” (4 feet) of pipe. • The launcher may be no longer than 24” (2 feet) in any dimension (height or length). • Before construction, the student must draft a detailed plan of the launcher. The student must follow this guideline and any modifications must be approved by the instructor.

To Make a Basic Launcher: • Cut the following lengths of PVC pipe: – 5 ½, 2 ½, 3 (2), 4 (2), 6 ½. – Attach the 5 ½ inch pipe to an elbow joint. Attach the 2 ½ inch pipe to this. Attach to T joint. On one side, attach a 3 inch pipe. Connect to an elbow joint. Connect to a 4 inch pipe, with an end cap. On the other side of the T joint, connect the 6 ½ inch pipe. Attach T joint. Attach 4 inch pipe, capped off on the bottom of the T. Attach 3 inch pipe to the end. – Start launching marshmallows!

If you did it correctly, it should look like this

Variations • Have fun with this! What designs can you come up with? – Which layout of pipe works best? – Which shoots furthest? – Most accurately?

Have fun with this!

Summary The design of the launcher will dramatically affect the distance a marshmallow may be launched.

Name: 1. Itemize the parts used: Date: 2. What is the furthest distance your design launched a marshmallow? 3. Which design worked best? 4. Was your design better than a straight piece of PVC of the same length? 5. If so, why? 6. What are some other practical applications of the Bernoulli Principle?