3D Print Projects

This is a demonstration of wave motion, showing how waves transfer energy without transferring matter.

This version uses a 10 mm ball bearing that moves up and down to model the oscillation of particles in a wave. In a wave, particles vibrate about fixed positions and pass energy to neighbouring particles, allowing the disturbance to move through the medium. The particles themselves do not travel with the wave.

For example, in water waves, the water moves up and down while the wave travels across the surface. This shows that the wave carries energy, not matter.

This apparatus demonstrates the relationship between photon energy and the frequency of light. It uses LEDs of different wavelengths, allowing students to measure the potential difference across each LED when it just turns on. This threshold voltage can then be compared with the frequency of the emitted light to estimate Planck's constant.

The apparatus is powered using a lab bench power supply set between 4 V and 6 V. A voltmeter can be connected across the LED to measure the potential difference at the point where the LED begins to emit light. For the UV and IR LEDs, an ammeter can also be connected to help identify when current starts to flow, as the light may not be visible to the eye.

This provides a useful demonstration of the link between electric potential difference, photon energy and the quantum model of light.