5*3 What do you see? (observation/claim/question)
5-3 WDYT Write the question, and TRY to answer it … 5-3 WDYT Write the question, and TRY to answer it ….remember…any THOUGHTFUL answer is ‘correct--
5*3 Notes: Revisiting Sounds in vibrating Strings Draw AND label a STANDING WAVE The length of the string = ½ λ OR 2×length=λ
λ is INVERSELY related to the f (pitch) 1. Frequency and Wavelength Wavelength (λ) = 2× length of string ½ λ = length of string The higher the pitch, the __greater _ the frequency The longer the string, the __longer_ the wavelength λ is INVERSELY related to the f (pitch)
Tension is DIRECTLY related to f (pitch) 2. Tension of a String & Frequency An increase in tension needs a larger force A larger force will make a greater acceleration A greater acceleration generates a faster vibration A faster vibration = A faster velocity Tension is DIRECTLY related to f (pitch)
Mass is INDIRECTLY related to f (pitch) 3. Thickness of a String & Frequency Thicker strings = Lower frequency and pitch Heavier mass = smaller acceleration Slow acceleration = slow velocity Mass is INDIRECTLY related to f (pitch)
VELOCITY is DIRECTLY related to f (pitch) VELOCITY OF VIBRATION AND PITCH Wavelength, mass and tension ALL relate back to the SPEED at which an instrument’s string vibrates VELOCITY is DIRECTLY related to f (pitch)
Standing Waves Is There an Equation??? Standing Waves occur when the length of the string and wavelength have a particular relationship L = (n × λ) λ = (2 × L) n = (2 × L) 2 n λ ***n = # of antinodes in the standing wave*** (ALL instruments only have 1 antinode!!!)
SAMPLE PROB #1 What is the length of the following standing wave, if the wavelength is 10 m?