New
New
Year 10
Edexcel
Higher

Measuring waves in a ripple tank

I can accurately measure the wavelength, frequency and wave speed of water waves in a ripple tank.

New
New
Year 10
Edexcel
Higher

Measuring waves in a ripple tank

I can accurately measure the wavelength, frequency and wave speed of water waves in a ripple tank.

Share activities with pupils
Share function coming soon...

Lesson details

Key learning points

  1. Frequency of a wave can be measured indirectly from its speed and wavelength.
  2. Wavelength of a wave can be measured by using a freeze frame of a wave moving along the length of a ruler.
  3. It is more accurate to measure the length of, e.g. ten waves and dividing by ten, than measuring one wavelength.
  4. Speed of a wave can be measured by recording the wave moving along a ruler with a timer in the frame.
  5. 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.

The investigation could alternatively be carried out as a demonstration, perhaps using a visualiser.
Teacher tip

Content guidance

  • Equipment requiring safe usage.
  • Contains flashing images.

Supervision

Adult supervision recommended.

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

Loading...

6 Questions

Q1.
In which of the following directions does the water move in a water wave?
forwards and backwards
side to side
Correct answer: up and down
Q2.
Which of the following accurately describes a water wave?
longitudinal
mechanical
Correct answer: transverse
Q3.
In which of the following directions should a wooden beam move in a trough of water to create water waves?
Correct answer: up and down
side to side
forwards and backwards
Q4.
Which of the following type of results do repeat measurements help to identify?
accurate results
Correct answer: anomalous results
average results
Q5.
A result is if it is very different from other measurements of the same variable.
Correct Answer: anomalous, wrong, a mistake
Q6.
Which of the following measurements are needed to find the frequency of a water wave?
distance and time
wavelength and time
Correct answer: wavelength and speed

6 Questions

Q1.
Which of the following pieces of equipment can be used to observe the behaviour of water waves in the classroom?
water tank
Correct answer: ripple tank
glass trough
Q2.
The frequency of a water wave equals the number of waves second.
Correct Answer: per, each, every, in one
Q3.
Which of the following happens if the motor controlling the wooden beam on a ripple tank is made to spin faster?
Correct answer: The frequency of the waves increases.
The speed of the wave increases.
The wavelength of the wave increases.
Q4.
The wave speed of a water wave equals the multiplied by the wavelength.
Correct Answer: frequency, f
Q5.
The frequency of a water wave equals the wave speed divided by the ...
Correct answer: wavelength.
frequency.
amplitude.
Q6.
Starting with the most accurate, sort these methods of measuring the wavelength of a water wave into order of decreasing accuracy.
1 - Measure the length of ten waves and divide the answer by ten.
2 - Measure the length of one wave three times and calculate the average.
3 - Measure the length of one wave once.

Additional material

Download additional material
We're sorry, but preview is not currently available. Download to see additional material.