Wave Speed Examples in Physics

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Wave Speed.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Physics.

Concept Recap

The speed at which a wave pattern propagates through a medium, determined by the medium's properties.

How fast the wave's shape moves forward through whatever it's traveling in.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Wave speed is determined by the medium it travels through, not by its frequency or source.

Common stuck point: Wave speed is fixed by the medium—changing frequency changes wavelength, not speed.

Sense of Study hint: When solving a wave speed problem, identify the frequency f and wavelength \lambda from the question. Then substitute into v = f\lambda and compute. If given period T instead of frequency, first convert using f = 1/T before applying the wave equation.

Worked Examples

Example 1

easy
A sound wave has a frequency of 440 \text{ Hz} and a wavelength of 0.773 \text{ m}. What is the speed of sound?

Solution

  1. 1
    Use the wave equation: v = f\lambda.
  2. 2
    Substitute the given values: v = 440 \times 0.773.
  3. 3
    v = 340.1 \text{ m/s}

Answer

v \approx 340 \text{ m/s}
The wave equation v = f\lambda applies to all types of waves. The speed of sound in air at room temperature is approximately 340 \text{ m/s}.

Example 2

medium
A seismic wave travels 60 \text{ km} in 10 \text{ s}. What is its speed? If the frequency is 2 \text{ Hz}, what is the wavelength?

Example 3

medium
A sound wave has frequency 440 Hz and wavelength 0.773 m. Calculate the speed of sound.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

medium
An electromagnetic wave has a frequency of 5 \times 10^{14} \text{ Hz}. What is its wavelength? Use c = 3 \times 10^8 \text{ m/s}.

Example 2

medium
The speed of sound in air at 20°\text{C} is 343 \text{ m/s} and in water is 1480 \text{ m/s}. A 500 \text{ Hz} tone travels from air into water. Does the frequency or wavelength change? Calculate the wavelength in each medium.
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Related Concepts

WavelengthFrequency

Background Knowledge

These ideas may be useful before you work through the harder examples.

wavelengthfrequency