Loading...
Amplitude = 5 5 4 3 2 1 0 1 2 3 4 5 y = sinx y = 5sinx ? 2 ? 3? 2 2? University of Minnesota Frequency, Wavelength and Period
The terms period and frequency are related by the following equation: 1 A string vibrates at a frequency of 20 Hz What is its period? 2 A speaker vibrates at a frequency of 200 Hz What is its period? 3 A swing has a period of 10 seconds What is its frequency? 4 A pendulum has a period of 0 3 second What is its frequency? 5 You want to
B= 2, the frequency doubled, and the period is cut in half 8 (a)For y = sin(4x), the wave should be four times as narrow, so that instead of going through a full wave every 2?, it goes through a full wave four times as fast, or every ? 2 (b)The wavelength or period is ? 2 In general, the period is 2 B (c)The frequency in this example is
10 The wavelength or period is ? 2 In general, the period is 2? B 11 The frequency in this example is 4 2? In general, the frequency is B 2? 12 Here are the formulas for period and frequency 13 To draw a graph of y = sin(5x), we begin with the period, which is 2? 5 14 We will divide 2? 5 into 4 equal parts, each of which is 2?
Period (wavelength) is the x-distance between consecutive peaks of the wave graph Period = 2? B; Frequency = B 2? Use amplitude to mark y-axis, use period and quarter marking to mark x-axis University of Minnesota Frequency, Wavelength and Period
Conversely, the period is the reciprocal of the frequency, T = 1/ f Since the period is a time interval expressed in seconds (s), it is easy to see the close relationship between time interval and frequency The standard unit for frequency is the hertz (Hz), de?ned as events or cycles per second The frequency of electrical signals is often
5 A bus comes around 15 times in 8 hours Find the frequency and period of the bus 6 A pendulum has a frequency of 3 5 Hz How many swings occur in one minute? 7 The equation to calculate the period of a perfect pendulum is T = 2 008L , where L is in meters Calculate the frequency of a pendulum with a length of 45 0 cm 8