Physics Dept. Demonstration Manual

DVW07 - Resonance

Objective:

To illustrate resonance effects.

 
Apparatus:  
  • Tuning forks on resonant cases
  • Clamp
  • Rubber hammer


Method:

If one tuning fork is struck in the vicinity of the other and then held with the hand the other fork is heard to be vibrating. The clamp is used to show that frequencies must be matched.

The two resonant cases are aligned to achieve optimum coupling of the air mass at the throats. The unclamped fork is struck first. The clamped fork is then struck and the clamp adjusted to give an identical frequency. Both forks are silenced by hand. Then one fork is struck and then silenced. The other fork can be heard even though it was not struck, due to transfer of energy in a resonant system.