• The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second.
• The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude.

$$ F = \cfrac{1}{t} $$

$$ T = \cfrac{1}{f} $$

• The frequency determines the shrillness or pitch of a sound.
• If the frequency of vibration is higher we say that the sound is shrill and has a higher pitch. If the frequency of vibration is lower, we say that the sound has a lower pitch.

Compare sound of a baby with sound of a man. Even if both have same loudness, how they differ. Explain the factor which cause difference. [3 MARKS]

Wave Frequency ( Read ) | Physics