Measuring waves in a ripple tank | Exit Quiz | Oak National Academy

Which of the following pieces of equipment can be used to observe the behaviour of water waves in the classroom?

• water tank

• ripple tank

• glass trough

Answer explanation

The ripple tank can make small water waves that can be observed in the classroom.

The frequency of a water wave equals the number of waves ___ second.

Answer explanation

Frequency is the number of waves per second, which means the number of waves each second.

Which of the following happens if the motor controlling the wooden beam on a ripple tank is made to spin faster?

• The frequency of the waves increases.

• The speed of the wave increases.

• The wavelength of the wave increases.

Answer explanation

A faster motor vibrates the wooden beam in a ripple tank faster and increases the frequency of the water waves.

The wave speed of a water wave equals the ___ multiplied by the wavelength.

Answer explanation

Multiplying the length of one wave by the number of waves per second (the frequency) gives the distance travelled by a wave in one second (the wave speed).

The frequency of a water wave equals the wave speed divided by the ...

• wavelength.

• frequency.

• amplitude.

Answer explanation

The wave speed is the distance a wave travels in one second and dividing it by the wavelength gives the number of waves per second.

Starting with the most accurate, sort these methods of measuring the wavelength of a water wave into order of decreasing accuracy.

• Measure the length of one wave once.

• Measure the length of ten waves and divide the answer by ten.

• Measure the length of one wave three times and calculate the average.

Answer explanation

Measuring the length of ten waves and dividing by ten also divides any measurement errors by ten.