A wave is a disturbance in a medium that carries energy without a net movement of particles.
Wave speed is the distance a wave travels in a given amount of time.
Formula to calculate wave speed.
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Example:
What is the speed of an electromagnetic wave whose length is 3.5m and has a frequency of 100,000,000 Hz.
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Therefore, the speed of the wave is 350,000,000 m/s.