Transverse and longitudinal waves

Figure 16 is a diagram of part of a water wave.

Use data from Figure 16 to determine the amplitude of the wave.

Use data from Figure 16 to determine the wavelength of the wave.

wavelength =_........

The water wave shown in Figure 16 is generated in a large tank.

A student observes the wave.

Describe how the student could determine the wave speed of the wave.

When an earthquake happens, waves are transmitted through the Earth. Figure 17 is a diagram of a part of the Earth’s crust.

Earth’s surface

An earthquake happens at point X, 20 km below the Earth’s surface.

An earthquake wave from X is detected at point L.

This earthquake wave is a transverse wave.

State one other example of a transverse wave.

A point in the crust is labelled R in Figure 17. There is a rock at point R.

Describe the effect that this earthquake wave has on the rock at R as the wave passes through the rock.

You may add to Figure 17 to help your answer.

*(c) A scientist investigates a sample of an unknown radioactive material.

The scientist finds that the sample does not emit beta radiation.

The scientist sets up the experiment shown in Figure 18 and uses different absorbers to investigate alpha and gamma radiation.

The results are shown in Figure 19.

The count rates are rounded to two significant figures.

The background radiation was 18 counts per minute (cpm).

Discuss whether the sample emits alpha or gamma radiation or both.

Your answer should refer to

• the data shown in Figure 19

• how the data gives evidence for particular radiations.

Figure 5 is a diagram of part of a water wave.

Use data from Figure 5 to determine the amplitude of the wave.

Use data from Figure 5 to determine the wavelength of the wave.

wavelength =_........

The water wave shown in Figure 5 is generated in a large tank.

A student observes the wave.

Describe how the student could determine the wave speed of the wave.

When an earthquake happens, waves are transmitted through the Earth. Figure 6 is a diagram of a part of the Earth’s crust.

Earth’s surface

An earthquake happens at point X, 20 km below the Earth’s surface.

An earthquake wave from X is detected at point L.

This earthquake wave is a transverse wave.

State one other example of a transverse wave.

A point in the crust is labelled R in Figure 6. There is a rock at point R.

Describe the effect that this earthquake wave has on the rock at R as the wave passes through the rock.

You may add to Figure 6 to help your answer.

The wave from X reaches L 3.8 seconds after it passes through R.

The speed of the wave is 4500 m / s.

Calculate the distance between X and R.

Which row of the table shows two transverse waves?

Figure 16 is an energy diagram for a sound wave incident on a sound-insulating board.

sound-insulating

The incident energy is 0.25 J.

The absorbed energy is 67 % of the incident energy.

The reflected energy is 15 % of the incident energy.

Calculate the amount of the transmitted energy.

Give one way to reduce the percentage of energy transmitted through the sound-insulating board.

The ratio of the absorbed energy E_a to incident energy E_i is the coefficient of absorption of sound α.

The table in Figure 17 gives the coefficient of absorption for various materials.

Explain why rooms with carpets and curtains are less noisy than rooms without them.

Use the information given in Figure 17 in your answer.

* (d) Explain how sound waves can be used to determine the depth of the ocean directly underneath a boat.

You may draw a diagram to help with your answer.

Figure 7 shows a wave on the surface of water.

Which of the arrowed lines shows the amplitude of the wave?

Explain why the wave shown in Figure 7 is a transverse wave.

Figure 8 shows a ripple tank.

A screen is placed below the ripple tank.

The wave pattern produced by the ripples can be seen on the screen.

A student has a stop clock and a ruler.

Describe how the student could measure the frequency of the ripples.

Describe how the student could measure the wavelength of the ripples.

In a swimming pool, a wave is produced with a wavelength of 4.0 m and a velocity of 0.8 m / s.

Calculate the frequency of the wave.

State the unit of frequency.

Use the equation

v = f × λ

frequency of wave_........ unit_........

This question is about waves.

Figure 3 is a diagram of a water wave in a ripple tank.

State the number of crests of the wave between P and Q.

The distance between P and Q is 42 cm.

Calculate the wavelength of the water wave in Figure 3.

wavelength =_........

Describe how a student could determine the wave speed of the water wave in Figure 3.

Which row of the table is correct for sound waves ?

A sound wave has a frequency of 440 Hz and a wavelength of 0.75 m.

Calculate the wave speed of the sound wave.

wave speed =_........

Figure 12 shows part of a wave.

Use data from Figure 12 to calculate the wavelength of the wave.

Figure 13 shows a student sitting on the shore of a lake watching ripples on the surface of the water moving past a toy boat.

The student has a stopwatch.

Describe how the student could determine the frequency of the ripples on the lake.

The speed of a water wave is 1.5 m/s.

The frequency of the wave is 0.70 Hz.

Calculate the wavelength of this wave.

Use the equation

v = f × λ

Water waves are transverse waves.

Describe the difference between transverse waves and longitudinal waves.

Sound waves travel at 330 m/s in air.

A student sees a flash of lightning.

The student hears the sound of thunder 4.0 s later.

Calculate the distance from the student to the flash of lightning.

Use the equation

x = v × t

Figure 1 shows part of a wave.

Use data from Figure 1 to calculate the wavelength of the wave.

Figure 2 shows a student sitting on the shore of a lake watching ripples on the surface of the water moving past a toy boat.

The student has a stopwatch.

Describe how the student could determine the frequency of the ripples on the lake.

The speed of a water wave is 1.5 m/s.

The frequency of the wave is 0.70 Hz.

Calculate the wavelength of this wave.

Use the equation

v = f × λ

Water waves are transverse waves.

Describe the difference between transverse waves and longitudinal waves.

Figure 11 shows a large tank of water.

The tank of water is used to study water waves.

Water waves are transverse waves.

Give another example of a transverse wave.

Figure 12 shows a side view of part of the tank.

A water wave is moving from L to M.

Calculate the wavelength of the wave.

A technician stands at the side of the tank.

He counts the peaks of the waves as they pass him.

12 peaks pass the technician in a time of 15 s.

Calculate the frequency of the wave.

Figure 13 shows part of the inside of the Earth below the surface.

An earthquake starts at Q.

A seismic wave travels from Q to S.

The seismic wave is a longitudinal wave.

Draw arrows on Figure 13 to show how the rock at R moves when the seismic wave passes through R.

The frequency of the seismic wave is 12 Hz.

The wave speed of the seismic wave is 7 km / s.

Calculate the wavelength of the seismic wave, in metres.

Use the equation

A technician measured the frequency of the water wave in part (a) by counting how many waves passed him in 15 s.

Explain why this would not be a suitable method for measuring the frequency of the seismic wave in part (b)(ii).

Four students and their teacher do an experiment to measure the speed of sound in air.

The teacher stands at a distance and fires a starting pistol into the air. The students see the flash when the pistol is fired. They measure the time from when they see the flash to when they hear the bang.

A student drew a diagram of the arrangement as shown in Figure 7.

The students obtained a value of 240 m/s for the speed of sound.

The accepted value, in a science data book, is 343 m/s.

Calculate the difference between the students’ value and the accepted value as a percentage of the accepted value.

percentage difference =_........

When the distance was 100 m, the students measured the following times:

0.43 s 0.35 s 0.50 s 0.38 s

Explain why their times vary so much.

Explain one way the students might improve this experiment.

Figure 8 represents a sound wave coming from a loudspeaker and shows the effects on particles of the air at one instant in time.

Draw and label a distance of one wavelength in Figure 8.

Describe the motion of the particles as the wave travels through the air.

Which colour of visible light has the longest wavelength?

Some television remote controls use infrared radiation and other remote controls use radio waves.

Explain why an infrared remote control may not switch on the television from behind an armchair but a radio wave remote control always will.

Figure 2 is a diagram of a water wave.

A cork is floating on the water.

Use the scale on the diagram to measure the wavelength of the wave.

Describe the motion of the cork.

You should include how the cork moves relative to the direction of travel of the wave.

A different water wave has a wavelength of 0.25 m and a frequency of 1.5 Hz.

Calculate the wave speed.

A sound wave in air travels a distance of 220 m in a time of 0.70 s.

State the equation linking speed, distance and time.

Calculate the speed of the sound wave in air.

Figure 2 shows water waves spreading out from a source.

A student measures the wavelength of the waves.

He uses a ruler to measure the distance from one crest to the next crest.

Explain how to improve the student’s method for measuring the wavelength.

Sound waves are longitudinal waves.

Water waves are transverse waves.

Describe the difference between longitudinal waves and transverse waves.

Figure 7 shows a tuning fork.

When the prongs of the tuning fork are struck, the prongs vibrate in the directions shown by the arrows on Figure 7.

Describe how the vibrating tuning fork causes a sound wave to travel through the air.

You may add to the diagram if it helps your answer.

The following descriptions describe waves from different parts of the electromagnetic spectrum.

Complete each description by adding the name of the wave.

Use the name of each wave only once. Each description refers to a different part of the electromagnetic spectrum.

Description 1

used in cooking

used in short-range communication

typical wavelength 900 nm

Description 2

used in cooking

used in communication

typical wavelength 150 mm

Description 3

used in communication

produced by oscillations in electrical circuits

typical wavelength 150 m

Description 4

used in medical scanning

is emitted by the nucleus of an atom

typical wavelength 2.0 × 10⁻³ nm

When white light crosses the boundary between air and glass, it can split up into the colours of the spectrum.

Explain, in terms of speed, why the light behaves like this.