Properties of waves

Figure 2 shows the position of air particles in the path of a sound wave.

What do the labels P and Q represent?

Choose the answers from the box.

Sound waves are longitudinal waves.

What direction are the oscillations in a longitudinal wave?

Tick () one box.

At 45° to the direction of energy transfer

Parallel to the direction of energy transfer

Perpendicular to the direction of energy transfer

A teacher and a student made measurements to determine the speed of sound in air.

They used a device called a ‘starter pistol’.

A starter pistol makes a loud sound and produces a puff of smoke at the same time.

Figure 3 shows the teacher and the student 100 m apart.

This is the method used.

1. The teacher fires the starter pistol.

2. The student sees the puff of smoke and starts the stopwatch.

3. The student hears the sound from the starter pistol and stops the stopwatch.

4. The student records the time on the stopwatch.

Why did the student see the puff of smoke before hearing the sound?

The teacher and student repeated the experiment several times and calculated a mean value for the times recorded.

The mean value for the time was used to calculate the speed of sound in air.

Why is it good practice to calculate a mean value in an investigation?

Tick () one box.

To reduce the effect of random errors

To reduce the effect of systematic errors

To reduce the effect of zero errors

The sound wave produced had a wavelength of 0.12 m and a wave speed of 330 m/s.

Calculate the frequency of the sound wave.

Use the equation:

Choose the unit from the box.

Radio waves are one type of electromagnetic wave.

What are two properties of all electromagnetic waves?

Tick () two boxes.

A thin sheet of metal stops all electromagnetic waves.

All electromagnetic waves are longitudinal.

All electromagnetic waves have the same speed in a vacuum.

All electromagnetic waves transfer energy.

Water reflects all electromagnetic waves.

A teacher used a radio transmitter, a metal sheet and a radio receiver to demonstrate the reflection of radio waves.

Figure 9 shows the path of the radio waves from the transmitter to the metal sheet.

The teacher placed the radio receiver at positions A, B, C and D.

Which position was the radio receiver at when the radio waves were detected?

Tick () one box.

A B C D

The frequency of the radio wave was 2400 MHz.

The speed of the radio wave was 3.0 × 10⁸ m/s.

Calculate the wavelength of the radio wave.

Use the Physics Equations Sheet.

The aerial of the receiver absorbs radio waves.

Explain why the frequency of the alternating current in the receiver circuit depends on the frequency of the radio waves.

Figure 13 shows a ripple tank used to investigate the behaviour of water waves.

Describe a method a student could use to determine the frequency of the water waves.

Use the Physics Equations Sheet to answer Questions 10.3 and 10.4.

Which equation links frequency (f), wavelength (λ) and wave speed (v)?

Tick (✓) one box.

v = f λ

v = f² λ

Figure 14 shows the water waves in the ripple tank when viewed from above.

Figure 14 has been drawn to actual size.

The water waves have a frequency of 2.5 Hz.

Calculate the wave speed of the waves in Figure 14.

You should take measurements from Figure 14.

Ultraviolet, infrared and visible light are part of the electromagnetic spectrum.

Neon atoms can absorb electromagnetic radiation.

Figure 13 shows three of the energy levels around the nucleus of a neon atom.

The atom in Figure 13 has absorbed electromagnetic radiation.

What happens as an electron moves from energy level B to energy level A ?

Tick (✓) one box.

Light is absorbed

Light is emitted

Light is reflected

An electromagnetic wave has a speed of 300 000 000 m/s.

What is the speed of the wave in standard form?

Tick (✓) one box.

3.0 × 10⁷ m/s

3.0 × 10⁸ m/s

3.0 × 10⁹ m/s

Use the Physics Equations Sheet to answer questions 09.4 and 09.5.

Write down the equation that links frequency (f), wavelength (λ) and wave speed (v).

The electromagnetic wave has a frequency of 750 000 Hz.

Calculate the wavelength of the electromagnetic wave.

Give the unit.

Ultraviolet, infrared and visible light are part of the electromagnetic spectrum.

Neon atoms can absorb electromagnetic radiation.

Figure 1 shows three of the energy levels around the nucleus of a neon atom.

The atom in Figure 1 has absorbed electromagnetic radiation.

What happens as an electron moves from energy level B to energy level A ?

Tick (✓) one box.

Light is absorbed

Light is emitted

Light is reflected

An electromagnetic wave has a speed of 300 000 000 m/s.

What is the speed of the wave in standard form?

Tick (✓) one box.

3.0 × 10⁷ m/s

3.0 × 10⁸ m/s

3.0 × 10⁹ m/s

Use the Physics Equations Sheet to answer questions 01.4 and 01.5.

Write down the equation that links frequency (f), wavelength (λ) and wave speed (v).

The electromagnetic wave has a frequency of 750 000 Hz.

Calculate the wavelength of the electromagnetic wave.

Give the unit.

A student used a ripple tank to investigate water waves.

What type of wave is a water wave?

Tick (✓) one box.

A sound wave

A transverse wave

An electromagnetic wave

Figure 8 shows the ripple tank.

Describe how the water waves are produced in the ripple tank.

The student counted the number of waves reaching the end of the tank.

What other measurement is needed to calculate the frequency of the waves?

Figure 9 shows three different wave patterns produced on the white card.

Which pattern in Figure 9 shows the waves with the greatest frequency?

Give a reason for your answer.

Tick (✓) one box.

A B C

Another student investigated how the depth of water in a tray affected the speed of water waves.

Figure 10 shows the apparatus.

This is the method used.

1. Pour water at room temperature into a tray to a depth of 5 mm.

2. Lift one end of the tray 5 cm and then let it go.

3. Measure the time taken for the water wave to move across the tray.

4. Calculate the speed of the water wave.

5. Repeat steps 1 to 4 with different depths of water.

Give one control variable in the student’s investigation.

The student calculated the speed of the waves at each depth.

Figure 11 shows the results.

Draw a line of best fit on Figure 11.

What is the speed of the water wave when the depth of the water is 20 mm?

Use Figure 11.

Speed of water wave = __________________ metres per second

Waves transfer energy.

Radio waves are transmitted from a radio station and absorbed by a radio receiver.

What is created in the radio receiver when the radio waves are absorbed?

Tick (✓) one box.

An alpha particle

An alternating current

An ultraviolet wave

An X-ray

Radio waves may be refracted when they travel from one substance into another substance.

Which diagram shows the refraction of a radio wave?

Tick (✓) one box.

When the radio receiver is switched on, a sound wave is produced.

Give two differences between radio waves and sound waves.

Table 4 shows the speed of sound in different substances at two different temperatures.

Give three conclusions about the effect of temperature and the type of substance on the speed of sound waves.

A teacher used a ripple tank to show how varying the frequency affected the wavelength of water waves.

Figure 4 shows the apparatus.

This is the method used.

1. Turn on the lamp.

2. Adjust the power supply so that the wooden bar vibrates with a frequency of 10 Hz to produce waves on the water.

3. Take a photograph of the image of the waves projected onto the white card.

4. Measure the length of 5 waves from the photograph.

5. Calculate the wavelength of 1 wave.

6. Repeat steps 2 to 5 for different frequencies.

The method used by the teacher is better than measuring the length of only 1 wave directly from the white card.

Explain why.

The electromagnetic spectrum is made up of waves with different wavelengths and frequencies.

Draw one line from each type of electromagnetic wave to a use of that type of wave.

A student investigated how the type of surface affects the amount of infrared the surface radiates.

The student used a hollow metal cube.

Four of the surfaces of the cube were different.

This is the method used.

1. Fill the cube with hot water and seal it with a lid.

2. Measure the infrared radiation emitted from each surface using an infrared detector.

Figure 8 shows the equipment used.

Table 2 shows some of the variables in this investigation.

Identify each variable as an independent, dependent or control variable.

Tick (✓) one box in each row on Table 2.

One row has been completed for you.

Table 3 shows the results.

What was the resolution of the infrared detector?

Tick (✓) one box.

What was the range of temperatures recorded?

Complete Figure 9.

You should:

• plot the data from Table 3 as a bar chart

• label each bar.

Give one conclusion that can be made from the results in Table 3.

Which equation links frequency (f), wavelength (λ) and wave speed (v)?

Tick (✓) one box.

A radio wave has:

• a speed of 300 000 000 m/s

• a wavelength of 500 m

Calculate the frequency of the radio wave.

Give the unit.

Choose the unit from the box.

The electromagnetic spectrum is made up of waves with different wavelengths and frequencies.

Give the type of electromagnetic wave with the lowest frequency.

A wave has a wavelength of 2.5 km and a velocity of 300 000 000 m/s

Calculate the frequency of the wave.

Figure 4 shows equipment that is used to investigate the emission of infrared radiation from different colours of surface.

The four hollow metal cubes are each painted a different colour.

The cubes can be filled with hot water before the lid is put on.

Describe a method to investigate which colour of surface emits infrared radiation at the greatest rate.

Which colour of surface will emit infrared radiation at the greatest rate?

Tick (✓) one box.

It is important to identify people at airports who may have infectious diseases, such as measles.

Explain how cameras that detect the rate of infrared emission can identify people with infectious diseases such as measles.

Figure 11 shows a transverse wave.

Which arrow shows the amplitude of the wave?

Tick (✓) one box.

Which arrow shows the wavelength of the wave?

Tick (✓) one box.

A teacher demonstrated waves on a string.

Figure 12 shows the apparatus used.

This is the method used.

1. Switch on the signal generator and vibration generator so the string vibrates up and down.

2. Move the wooden bridge until a clear wave pattern is formed between the wooden bridge and the vibration generator.

3. Use a metre rule to measure the length of the string between the wooden bridge and the vibration generator.

4. Record the frequency of the wave from the signal generator.

5. Record the number of loops in the wave pattern. The wave pattern shown in Figure 12 has one loop.

6. Change the frequency on the signal generator until a new wave pattern is formed.

7. Repeat steps 4 to 6.

Give one control variable in this demonstration.

The length of the string between the vibration generator and the wooden bridge was about 1.5 m

The teacher used a metre rule to measure the length of the string.

Suggest two reasons why making an accurate measurement was difficult.

Table 7 shows the results.

Give one conclusion about frequency and wavelength from the data in Table 7.

Each loop of the wave pattern is the length of half a wavelength.

Determine wavelength X in Table 7.

Calculate the period of the wave when the frequency was 30 Hz

Give your answer to 2 significant figures.

Use the Physics Equations Sheet.

Figure 1 shows a transverse wave.

Which arrow shows the amplitude of the wave?

Tick (✓) one box.

Which arrow shows the wavelength of the wave?

Tick (✓) one box.

A teacher demonstrated waves on a string.

Figure 2 shows the apparatus used.

This is the method used.

1. Switch on the signal generator and vibration generator so the string vibrates up and down.

2. Move the wooden bridge until a clear wave pattern is formed between the wooden bridge and the vibration generator.

3. Use a metre rule to measure the length of the string between the wooden bridge and the vibration generator.

4. Record the frequency of the wave from the signal generator.

5. Record the number of loops in the wave pattern. The wave pattern shown in Figure 2 has one loop.

6. Change the frequency on the signal generator until a new wave pattern is formed.

7. Repeat steps 4 to 6.

Give one control variable in this demonstration.

The length of the string between the vibration generator and the wooden bridge was about 1.5 m

The teacher used a metre rule to measure the length of the string.

Suggest two reasons why making an accurate measurement was difficult.

Table 1 shows the results.

Give one conclusion about frequency and wavelength from the data in Table 1.

Each loop of the wave pattern is the length of half a wavelength.

Determine wavelength X in Table 1.

Calculate the period of the wave when the frequency was 30 Hz

Give your answer to 2 significant figures.

Use the Physics Equations Sheet.