GCSE Physics Revision "The Wave Equation"

This video will teach you how to use the wave equation to calculate wave speed and how to measure the speed of sound waves. It reviews key wave properties: amplitude (farthest vibration from undisturbed position), wavelength (distance between equivalent points on adjacent waves), and frequency (number of waves passing a point per second, measured in Hertz). The video then introduces wave speed, defined as the speed at which a wave moves through a medium or energy is transferred.

The wave speed, measured in meters per second, is calculated by multiplying the frequency (in Hertz) by the wavelength (in meters). This equation is not provided in exams, so it must be memorized. A triangular mnemonic is also presented to help remember the formula and its rearrangements.

A wave has a frequency of 165 Hertz and a wavelength of 2 meters. To calculate its speed, multiply 165 Hz by 2 m, resulting in a wave speed of 330 meters per second.

A wave has a frequency of 10,000 Hertz and a wavelength of 2 centimeters. First, convert the wavelength from centimeters to meters by dividing by 100 (2 cm = 0.02 m). Then, multiply 10,000 Hz by 0.02 m to get a wave speed of 200 meters per second.

A wave has a speed of 500 meters per second and a frequency of 200 Hertz. To calculate the wavelength, rearrange the wave equation to divide wave speed by frequency. Dividing 500 m/s by 200 Hz gives a wavelength of 2.5 meters.

To measure the speed of sound, two people are positioned 500 meters apart. Person A clashes cymbals, and Person B starts a timer upon seeing the clash and stops it upon hearing the sound. The speed of sound is then calculated by dividing the distance (500m) by the timed interval.

Problems with the sound speed experiment include human reaction time. This error can be reduced by using multiple observers and calculating a mean value, discarding anomalous results. The short time interval between seeing and hearing also poses a challenge; increasing the distance between the participants lengthens this interval, making timing more accurate.