3D40.55 - Glass Breaking with Sound

This classic demonstration of resonance uses intense sound waves whose frequency is tuned to match the natural frequency of a glass goblet. The glass has a high lead content, which produces the high quality factor, Q, required for this demonstration. The “quality” of the glass can be heard by noting how long it rings after tapping. The natural frequency of the particular goblet to be used is carefully measured before the demonstration to within ~ 0.1 Hz. When driven by the amplifier and speake...

5K10.20 - Induction Coil with Magnet

Faraday’s induction law is clearly demonstrated here. The magnetic field lines emanating from the end of the bar magnet are fringed. As the magnet is moved towards or away from the coil’s center (or as the magnet is held stationary and the coil moved), the magnetic flux through an imaginary surface bounded by the coil’s loops varies in time. As a consequence, an induced electric field in the coil produces a current that is evident on the ammeter.

5H30.15 - Bending an Electron Beam

3B22.10 - Standing Waves on a String

A standing wave is the superposition of traveling waves constrained between two fixed boundaries, resulting in a discrete set of modes.

6A42.21 - Nakamura Refraction Tank

3B40.10 - Doppler Buzzer

3B25.25 - Spring Wave Reflections

The reflection at a fixed end is inverted because the incoming pulse exerts a force on the rigid boundary that is opposite in direction to the reaction force the boundary exerts on the spring. The reflection at a free end is not inverted. If the mass density of the spring is μ1 and that of the boundary is μ2, then a fixed end reflection is modeled by μ2>>μ1 and vice-versa for a free end reflection. In the demonstration, a fixed end is accomplished by attaching the spring to the rod clamp while...

1C10.27 - Air Track and Glider Velocity

Demonstrates the concept of velocity as a distance traveled divided by the time taken.

1D15.20 - High Road, Low Road

The time required for each ball to traverse its path is the horizontal displacement divided by the average horizontal velocity. The High and Low Road paths have equal horizontal displacements, but the Low Road has the greater average horizontal velocity. Thus, the Low Road takes the lesser time. Why? Because the normal force of the Low Road track produces an instantaneous horizontal velocity that is always equal to or greater than the instantaneous horizontal velocity produced by the normal fo...

Balloon in a Vacuum (4E20.40)

Demonstrates Boyle's Law which states that, “For a fixed amount of gas kept at a fixed temperature, P and V are inversely proportional (while one increases, the other decreases)."Demo PDF