Measuring waves in a ripple tank
I can accurately measure the wavelength, frequency and wave speed of water waves in a ripple tank.
Measuring waves in a ripple tank
I can accurately measure the wavelength, frequency and wave speed of water waves in a ripple tank.
Lesson details
Key learning points
- Frequency of a wave can be measured indirectly from its speed and wavelength.
- Wavelength of a wave can be measured by using a freeze frame of a wave moving along the length of a ruler.
- It is more accurate to measure the length of, e.g. ten waves and dividing by ten, than measuring one wavelength.
- Speed of a wave can be measured by recording the wave moving along a ruler with a timer in the frame.
- Accurate distance and time are measured by freezing the film, played back in slow motion, to track one wave crest.
Common misconception
In the equation for the speed of a wave, v = f x λ, speed is dependent on frequency and/or wavelength.
Emphasise that the speed of a wave depends only on the wave medium and not on frequency or wavelength.
Keywords
Ripple tank - A vibrating beam in a ripple tank creates water waves in a clear bottomed container that makes the waves easier to observe.
Slow motion - A film played back in slow motion shows everything happening slowly, including the speed of a timer shown in the film.
Wave equation - The wave equation is: wave speed = frequency × wavelength, v = f × λ.
Uncertainty - The uncertainty in a measurement can be expressed as the range of values within which the true value must lie.
Significant figures - The number of significant figures of a measurement depends on how accurately the measurement is made.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
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