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Exhibit 12 - Fracture

SMF - Fracture Group 

What will the students see at the exhibit?

The students will see a demonstration of Newton’s law of motion using carriages on an air track. An air-powered "ping pong ball cannon" will demonstrate the physics of collisions and hopefully provide some excitement. We hope to use a high-speed camera to show the collision in more detail.

What physics is used?

Our exhibit has two elements that utilise different areas of physics.

The first is the creation of a small explosion using a capacitor bank and a wire filament. We will go through how energy can be stored in a capacitor and perhaps more generally. The energy stored will be calculated. The capacitor bank dumps the energy instantaneously into a wire filament. A comparison will be made with a filament bulb. The phase change that takes place in the bulb will be described and how the confined gas results in an explosion.

The second piece of physics is the use of Newton’s first and third laws. We will then demonstrate the conservation of momentum using the "ping pong cannon". This website contains a full description (http://www.physicsclassroom.com/class/momentum/Lesson-2/Momentum-Conservation-in-Explosions)

Why is it useful?

Understanding the physical properties of materials is useful so we can understand how they will behave in different environments. If you are designing a power distribution system you need to know how the components will respond. If you are designing a rocket you want to know if the amount of fuel you have is enough to take your rocket to space.