Which statement defines frequency?

Which statement defines frequency?

• A. The horizontal distance between crests or troughs
• B. The rarefaction
• C. How many wave peaks pass a certain point per given time
• D. How many wave peaks pass a certain point per given time

Answer: (D)

Frequency is the rate at which repeat events occur over time. For waves, it tells you how many wave peaks pass a fixed point in a given amount of time. That exact idea—how many peaks pass a point per unit time—defines frequency. The unit is hertz (Hz), meaning one peak per second equals 1 Hz. This is different from wavelength, which is the distance between successive crests (or troughs) and measures space, not time. It’s also not about rarefaction, which is a region of lower pressure in a longitudinal wave. So frequency specifically captures how often peaks arrive at a point per second. For example, if five peaks pass a point in one second, the frequency is five hertz.

Frequency is the rate at which repeat events occur over time. For waves, it tells you how many wave peaks pass a fixed point in a given amount of time. That exact idea—how many peaks pass a point per unit time—defines frequency. The unit is hertz (Hz), meaning one peak per second equals 1 Hz.

This is different from wavelength, which is the distance between successive crests (or troughs) and measures space, not time. It’s also not about rarefaction, which is a region of lower pressure in a longitudinal wave. So frequency specifically captures how often peaks arrive at a point per second. For example, if five peaks pass a point in one second, the frequency is five hertz.