5*3 Sounds in Strings Revisited WDYS??? (p508) . WDYT??? The pitch changes as you change the tension in the string because _____.

5*3 Investigate (p508) 3. Draw AND label a STANDING WAVE 4. The length of the string = ½ λ, therefore λ = 2× length of the string Length (cm) λ (cm) Pitch (low, medium, high)

5*3 Investigate (p508) 5a) The pitch (frequency) _____ as the string is made shorter while tension remains the same. 7a) The wavelength _____ as the string is made shorter while tension remains the same.

5*3 Investigate (p508) 8. The greater the tension (more mass), the higher the pitch…The length of the string stayed the same, therefore the λ remained the same… 8a) The wave property that changes when the tension in increased is the _____. Therefore, the faster the wave travels, the _____ the frequency and the _____ the pitch.

5*3 Physics Talk (p510) 1. Frequency and Wavelength Wavelength (λ) = 2× length of string Length of string = ½ λ The higher the pitch, the _____ the frequency, the _____ the string, the _____ the wavelength v = f × λ f = v / λ λ = v / f λ is INVERSELY related to the f (pitch)

5*3 Physics Talk (p510) 2. Tension of a String & Frequency An increase in tension produces a larger force A larger force will make a greater acceleration A greater acceleration generates a faster vibration A faster vibration = A faster velocity v = f × λ f = v / λ λ = v / f v is DIRECTLY related to f (pitch)

5*3 Physics Talk (p510) 2. Thickness of a String & Frequency Thicker strings = Lower frequency and pitch Increased mass = Increased force and tension Heavier mass = smaller acceleration Slow acceleration = slow velocity v = f × λ f = v / λ λ = v / f v is DIRECTLY related to f (pitch)

5*3 Physics Talk (p510) 3. 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***

5*3 Checking Up (p514) If you decrease the wavelength of a wave, the frequency ___. The equation for frequency is ___. Increasing the tension of the string _____ its pitch. When the tension of the string is increased, the wave speed _____; therefore, the speed of a wave is _____-related to its tension. The equation for length of coiled spring and the wavelengths of standing waves is _____.

5*3 Physics To Go (p517) Increasing the tension _____ the frequency of the vibrating string. Increasing the length of the string _____ the wavelength of the pattern. To keep the frequency the same, the length and the tension _____. The wavelength and frequency would BOTH change if the length _____ and the tension _____. If BOTH length and tension increased OR decreased TOGETHER, the pitch would change.

5*3 Physics To Go (p517) 5. The guitarist changes the tension in the vibrating strings in order to change the _____ which leads to a change in pitch. 6. The more massive the string, the _____ the wave speed and the _____ the frequency and pitch.

5*3 Quiz .