Waves: Transverse & Longitudinal (CIE A Level Physics)

Sound travels with a speed of 330 m s^–1 in air. The variation with time of the displacement of an air particle due to a sound wave is shown below.

Which of the following statements about the wave is correct?

The graph shows two light waves travelling at the same frequency.

Which of the following could be the phase difference between the two waves?

The diagram shows a wave moving along a stretched rope in the direction shown.

Which of the following will be the correct graph to show the variation with time t of the displacement s of the particle Q in the rope ?

A wave is travelling through a medium at 24 m s^–1 with a frequency of 15 Hz.

What is the phase difference between two points 2 m apart?

A plan polarised light of amplitude A is passed through a polarising filter as show in the diagram. The emerging light has an amplitude of A cos

 

If the intensity of the beam is I, what is the intensity of the emerging light when θ is 60.0˚?

A police car siren emits a sound wave with a frequency f_s of 440 Hz. The car is travelling away from an observer at a speed of 30 m s⁻¹.

 The speed of sound is 340 m s⁻¹.

 Which of the following is the frequency the observer hears?

What is the frequency, amplitude and period of the wave shown in the graph below, to 2 significant figures?

	Period / s	Frequency / Hz	Amplitude / m
A B C D	0.0042 0.0035 0.0031 0.0027	240 290 320 290	0.013 0.0065 0.013 0.0065

A sound wave with an amplitude a of 0.2 mm has an intensity of 2.5 W m^–2

 If a wave with the same frequency has an amplitude of 2a what is the intensity of the wave?

A sound wave can be displayed on a cathode ray oscilloscope (C.R.O.). The time base is set to 5 μs mm^-1.

What is the frequency of the sound wave?

The graph shows the displacement of a sound wave over time.

 

When the intensity of the wave is halved, which graph shows the correct displacement of the wave ?

A source of sound power P is situated in an open space. The intensity I of sound at distance r from this source is given by

                     

How does the amplitude A of the vibrating air molecules vary with the distance r from the source ?

The equation below shows the speed of v waves in deep water

                      

 Where g is the acceleration of free fall and λ is the wavelength of the waves. The wavelength λ and the frequency f of the wave were measured. 

If the graph was to give a straight line through the origin which of the following graphs should be plotted?

The graph shows two waves P and Q.

Wave P has an amplitude of 8 cm and a frequency 100 Hz.

 What is the amplitude and the frequency of wave Q?

	Amplitude / cm	Frequency / Hz
A B C D	4 4 2 2	300 33 300 33

The graph below shows two sound waves, the sound wave is a series of moving pressure variations.

Wave 1 has an intensity of 1.6 × 10^–6 W m^–2, what is the intensity of wave 2 ?

A light wave is incident normally on a surface of area S with an amplitude A. The power per unit area reaching the surface is P.

 If the light is focused on a smaller area of   , and the amplitude of wave is doubled to 2A what is the power per unit area?

All electromagnetic waves travel at speed c in a vacuum with a frequency f and wavelength λ.

 Which row in the table describes the wavelength and speed of electromagnetic waves with a frequency   ? 

	Speed in a vacuum	Wavelength
A	2c	2λ
B	c	2λ
C	c
D

Sound waves can be displayed on a cathode ray oscilloscope (C.R.O.). The graph below represents two waves seen on the screen. They are labelled P and Q as shown in the diagram

What is the ratio   ?

The intensity I of a sound at point Q is inversely proportional to the square of the distance x of Q from the source of the sound. This can be shown by the equation

                           

           

Molecules of air at Q are a distance r from S and oscillate with amplitude 8.0 μm.

Point T is a distance 2r from S.

 What is the amplitude of oscillation of air molecules at T?

The graph shows a sinusoidal wave in water travelling at a speed of 8.0 m s^–1.

The maximum speed of the particles in the wave is , where a is the amplitude and f is the frequency.

An object Q is floating on the water it has a mass of 2.5 × 10^–3 kg.

What is the maximum kinetic energy of Q due to the wave? Assume the motion is vertical.

A wave has a speed of 340 m s^–1 and a frequency of 500 Hz

 If two points on a wave are 0.17 m apart, what is the phase difference?

The sun emits light of a particular wavelength λ_s. At any instant, there is a range of wavelengths from less than λ_s to greater than λ_s­ that can be observed on Earth. This is due to the Doppler effect.

 Which of the following statements would explain this Doppler effect?