Progressive Waves (CIE AS Physics)

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 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 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?

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?

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?