Answer Happy

GOAL Perform elementary calculations using speed, wavelength, and frequency. PROBLEM A wave has a wavelength of 3.00 m. Calculate the frequency of the wave if it is (a) a sound wave and (b) a light wave. Take the speed of sound as 343 m/s and the speed of light as 3.00 x 108 m/s. SOLUTION (A) Find the frequency of a sound wave with a = 3.00 m. (1) V Solve the equation for the frequency and substitute. f = 1 343 m/s 3.00 m 114 Hz (B) Find the frequency of a light wave with i = 3.00 m. с Substitute into Equation (1), using the speed of light for c. 3.00 x 108 m/s 3.00 m 1.00 x 108 Hz
PRACTICE IT Use the worked example above to help you solve this problem. A wave has a wavelength of 3.40 m. Calculate the frequency of the wave if it is each of the following types of waves. Take the speed of sound as 343 m/s and the speed of light as 3.00 x 108 m/s. (a) a sound wave 100.8 HZ (b) a light wave 0.88E8 Hz EXERCISE HINTS: GETTING STARTED I I'M STUCK! (a) Find the wavelength of an electromagnetic wave with frequency 8.55 GHz = 8.55 x 10 Hz (G = giga = 10%), which is in the microwave range. i = 0.35E8 x What is the speed of an electromagnetic wave? What is the given frequency? Therefore, what is its wavelength? m a (b) Find the speed of a sound wave in an unknown fluid medium if a frequency of 523 Hz has a wavelength of 2.75 m. v = 1234.2 X Follow the example, but not too closely. A relationship from the textbook might be more useful that any of those given in the example. m/s