RHYTHM is GONNA GET YOU? (Resonance)
Students do not know what resonance is, and yet they utilize it frequently. When objects resonate, energy is added to a system as just the right time to affect change. In example, when you swing a child on a swing, you don’t push them as they are headed towards you, you push them just after they stop, and are about to move away again. This adds energy to the system, rather than removing it so that the child can go higher and faster than they were previously.
22. Lift A Person with One Finger |
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| In this demonstration, a person will bounce from a spring mounted on the ceiling. With the simple tap of a finger, from another person, we will see the amplitude of the oscillation dramatically change. This occurs because the energy is being added to the system at the right time. | |
23. Tuning Forks |
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| Similarly to motion, sound is the same way. When energy is added to an object at the right time, it will cause motion or vibration in the other object. Using tuning forks, resonance can be demonstrated by tapping one fork, and then allowing the audience to hear the second tuning fork ringing afterwards. | |
24. Breaking Glass |
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 Using sound waves, tuned to the right frequency, you can get glass to resonate. We can observe this phenomenon by placing a ping pong ball into the glass, and watching it bound around in the glass. However, without the ping pong ball, it is difficult to see the effect. Using a strobe light, we can then observe the actual movement in the glass. If we tune the speaker to the right frequency (adding energy to the glass at the right time), the glass will vibrate so much it will break. |
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