GCSE Physics Revision "Required Practical 8: Ripple Tank"

Summary

In this video, the process of using a ripple tank to measure the wavelength, frequency, and speed of water waves is explained. The setup includes a shallow tank of water with a vibrating bar that creates waves. The wavelength is measured by counting 10 waves, while the frequency is determined by counting waves in 10 seconds and dividing by 10. The wave speed is calculated using the wave equation, multiplying frequency and wavelength. Measurement errors may arise from different methods, but overall, the video provides a detailed guide to this required practical experiment.

Takeaways

• 😀 A ripple tank is a shallow tray of water with a vibrating bar that creates waves across the water's surface.
• 😀 The setup includes a power pack that makes the bar vibrate, producing waves on the water's surface.
• 😀 A sheet of white paper placed below the tank is used to capture the wave patterns when light passes through the water.
• 😀 To measure the wavelength, a ruler is placed on the paper to measure the distance between 10 waves, and then the total is divided by 10.
• 😀 The wavelength in this example was measured to be 0.026 meters for 10 waves, which gives a wavelength of 0.0026 meters for one wave.
• 😀 Frequency is the number of waves passing a point every second, and it can be measured by counting the waves in 10 seconds and dividing by 10.
• 😀 In this case, 24 waves passed a point in 10 seconds, giving a frequency of 2.4 Hertz.
• 😀 The speed of the waves can be calculated using the wave equation: wave speed = frequency × wavelength.
• 😀 Using the values from the example, a frequency of 2.4 Hertz and a wavelength of 0.026 meters, the wave speed was calculated as 0.0624 meters per second.
• 😀 Alternatively, the wave speed can be determined by measuring the time it takes for a wave to travel the length of the tank, and dividing the distance by the time.
• 😀 Measurement errors may cause slight differences in results when calculating wave speed using different methods.

Q & A

What is a ripple tank and how is it used?

A ripple tank is a shallow tray of water used to observe the features of water waves. It has a vibrating bar connected to a power pack, which generates waves across the surface of the water. The waves are then projected onto a sheet of white paper beneath the tank, where their features can be analyzed.

How does the ripple tank setup allow for measuring wave properties?

The ripple tank setup allows for measuring wave properties by projecting light through the water, creating a visible image of the waves on paper below the tank. Using a mobile phone to record the waves enables the playback of the video at different speeds or freezing the image, which helps in measuring wavelength, frequency, and wave speed.

What is the first step in measuring the wavelength of the waves?

The first step in measuring the wavelength is to place a ruler on the paper and freeze the image of the waves. Then, measure the distance between one wave and 10 waves, which gives the total distance for 10 wavelengths.

How do you calculate the wavelength from the total distance of 10 waves?

To calculate the wavelength, divide the total distance measured for 10 waves by 10. For example, if the total distance for 10 waves is 26 centimeters, divide it by 10 to get 0.026 meters, which is the wavelength for each wave.

What is the definition of frequency in the context of this experiment?

Frequency refers to the number of waves passing a point each second. In the context of this experiment, it is measured by counting the number of waves that pass a specific point within a certain time frame.

What method is suggested to measure the frequency of waves?

The recommended method is to count the number of waves passing a point in 10 seconds and then divide that number by 10 to calculate the frequency in waves per second (Hertz). Using a timer and recording the waves in slow motion also helps improve accuracy.

What frequency was measured in the example given in the transcript?

In the example, 24 waves passed a point in 10 seconds. Dividing 24 by 10 gives a frequency of 2.4 waves per second, or 2.4 Hertz.

How is the speed of the waves determined in this experiment?

The speed of the waves is determined using the wave equation: speed = frequency × wavelength. In the example, the frequency is 2.4 Hz and the wavelength is 0.026 meters, so multiplying these values gives a wave speed of 0.0624 meters per second.

What is an alternative method to calculate the speed of waves?

An alternative method to calculate the wave speed is to select a wave and measure the time it takes to travel the length of the ripple tank. The speed is then calculated by dividing the distance traveled by the time taken.

Why might there be different results when calculating wave speed using the two methods?

The results might differ due to measurement errors, such as inaccuracies in timing or in the measurement of the wave's distance. These small errors can lead to variations in the calculated wave speed.