Define frequency and wavelength in a wave, and how are they related to the speed of the wave?

Define frequency and wavelength in a wave, and how are they related to the speed of the wave?

• A. Frequency is cycles per second; wavelength is distance per cycle; speed = frequency ÷ wavelength
• B. Frequency is cycles per second; wavelength is distance per cycle; speed = frequency × wavelength
• C. Frequency is cycles per minute; wavelength is distance per cycle; speed = frequency × wavelength
• D. Frequency measures amplitude; wavelength measures speed; speed = amplitude × frequency

Answer: (B)

The main idea is how frequency and wavelength determine the speed of a wave. Frequency is how often the wave repeats in a given time, measured in cycles per second (hertz). Wavelength is the distance over which one complete cycle repeats, measured in meters. The speed of a wave is how far its crests travel in one second, which comes from multiplying how many cycles occur each second by how far one cycle extends: speed = frequency × wavelength. For example, if a wave has a frequency of 2 cycles per second and a wavelength of 3 meters, its speed is 6 meters per second. Amplitude describes the height of the wave, not how fast it travels, and the frequency unit must be per second for the standard relation to hold.

The main idea is how frequency and wavelength determine the speed of a wave. Frequency is how often the wave repeats in a given time, measured in cycles per second (hertz). Wavelength is the distance over which one complete cycle repeats, measured in meters. The speed of a wave is how far its crests travel in one second, which comes from multiplying how many cycles occur each second by how far one cycle extends: speed = frequency × wavelength. For example, if a wave has a frequency of 2 cycles per second and a wavelength of 3 meters, its speed is 6 meters per second. Amplitude describes the height of the wave, not how fast it travels, and the frequency unit must be per second for the standard relation to hold.