1. Unit 9 Notes
Waves

2. T is Period of oscillation
T is Period of oscillation. It is the time it takes to complete one full oscillation. f is frequency. It is the number of full oscillations that occur in some amount of time (usually 1s). A is Amplitude. It is the magnitude of the greatest value of the oscillation
𝑻= 𝟏 𝒇

3. Pendulums
𝑻=𝟐𝝅 𝒍 𝒈
Because the restorative force is gravity, the acceleration is independent of mass.

4. Oscillating Spring 𝑻=𝟐𝝅 𝒎 𝒌
𝑻=𝟐𝝅 𝒎 𝒌
Amplitude is the furthest distance from equilibrium.
Restorative force is the spring force. Divide that by the mass for acceleration.
Side note:
F = -k∆x – in a spring
F = ma
ma = -k∆x

5. Crest: The highest point. Trough: The lowest point
Crest: The highest point. Trough: The lowest point. Wavelength: The distance between corresponding parts of adjacent waves (crest to crest, trough to trough, etc) -the length of the full wave

6. Standing Waves
When there are waves traveling both ways through a medium (such as a string), they will interfere with each other. Node: A point where the waves cancel each other out. Anti-Node: A point of maximum oscillation half way between nodes.

7. v = f λ
v is velocity of the wave. f is frequency of the wave λ is the wavelength.

8. Reflections
Fixed End: The wave returns on the opposite side (if it was on the left, it’s now on the right. If it was on the top, it’s now on the bottom). Outgoing: Returning:

9. Free End: The wave returns on the same side. Outgoing: Returning:

10. Changing Media
From heavy to light: Part of the wave reflects. Most of the wave transmits. Both end up on the same side as the original wave.

11. From Light to Heavy. Part of the wave is reflected and part is transmitted. The reflected part switches sides while the transmitted part stays on the same side.