2012

IV Oscillations and waves | мαтнy

CIE AS amp A LEVEL PHYSICS

14 Oscillations 1048633

15 Waves 1048633

16 Superposition 1048633

Simple Harmonic Motion is an oscillatory motion in which acceleration is always proportional to its displacement from a fixed point and is directed towards that point

See Q3 of June2003

Candidates should realise that both a sine wave and a cosine wave are sinusoidal

State the effect if any on the appearance of the fringes observed on the screen when the following changes are made separately to the double-slit arrangement

-the width of each slit is increased but the separation remains constantsame separation bright areas brighter dark areas no change fewer fringes observed

-the separation of the slits is increasedsmaller separation of fringes no change in brightness

Progressive wave

frequency number of oscillations per unit time M1of the source of a point on the wave A1 [2]

speed

speed at which energy is transferred speed of wavefront

Standing wave

does not transfer energy (along the wave)

position (along wave) where amplitude of vibration is a maximum is called the anti node

once we getstress = force area so area = force stressarea = (19 times 103) (95 times 108)= 20 times 10ndash6 m2now this is the minimum area the rod should have so that it does not break(lesser shall it be the rod

would break) and this can only be such when the area of bubble is its maximum(max) area of cross-section = (32 ndash 20) times 10ndash6= 12 times 10^ndash6when bubble has 12 x 10^-6 rod has 2 x 10^-6 a total of 32 x 10^-6 n07 q4c

coherent = constant phase difference

Progressive wave = transfer of energy as a result of oscillations vibrations of a particles

Nrsquo091 Q5c for diffraction and interference

State what is meant by resonance

1 large maximum amplitude of vibration B12 when impressed frequency equals natural frequency of vibration B1

State and briefly explain a situation in which resonance should be avoided

1 eg metal panels on machinery vibrate oscillate (M1)motor in machine impresses frequency on panel (A1)

2 eg car suspension system vibrates oscillates (M1)going over bumps would give large amplitude vibrations (A1)

Damping

1 either loss of energy (from the system) or amplitude decreases or additional force acting (on the mass)

2 either continuousgradual loss or force always opposing motion

it is the reduction in amplitude due to friction

Resonance

HarmfulThe operation of the engine of a vehicle causes a periodic force on the parts of the vehicle which can cause them to resonate For example at particular frequencies of rotation of the engine the mirrors may resonate To prevent excessive vibration the mountings of the mirrors provide damping

UsefulMusical instruments rely on resonance to amplify the sound producedThe sound from a tuning fork is louder when it is held over a tube of just the right length so that the column of air resonates

Radian- angle (subtended) at centre of circle (by) arc equal in length to radius

Oscillations to-and-fro backward and forward motion (between two limits)

Free oscillations no energy loss or gain no external force acting constant energy constant amplitude

Potential energy of the body ability to do work as a result of the positionshape etc of an object

Speed of the stationary wave

wave is reflected at end at P B1either incident and reflected waves interfereor two waves travelling in opposite directions interfere M1speed is the speed of incident or reflected wave one of these waves A1

Features of a stationary wave that distinguishes it from a progressive wave

no energy transfer amplitude varies along its lengthnodes and antinodes neighbouring points (in inter-nodal loop) vibrate in phase

14 Oscillations 1048633

15 Waves 1048633

16 Superposition 1048633

Simple Harmonic Motion is an oscillatory motion in which acceleration is always proportional to its displacement from a fixed point and is directed towards that point

See Q3 of June2003

Candidates should realise that both a sine wave and a cosine wave are sinusoidal

State the effect if any on the appearance of the fringes observed on the screen when the following changes are made separately to the double-slit arrangement

-the width of each slit is increased but the separation remains constantsame separation bright areas brighter dark areas no change fewer fringes observed

-the separation of the slits is increasedsmaller separation of fringes no change in brightness

Progressive wave

frequency number of oscillations per unit time M1of the source of a point on the wave A1 [2]

speed

speed at which energy is transferred speed of wavefront

Standing wave

does not transfer energy (along the wave)

position (along wave) where amplitude of vibration is a maximum is called the anti node

once we getstress = force area so area = force stressarea = (19 times 103) (95 times 108)= 20 times 10ndash6 m2now this is the minimum area the rod should have so that it does not break(lesser shall it be the rod

would break) and this can only be such when the area of bubble is its maximum(max) area of cross-section = (32 ndash 20) times 10ndash6= 12 times 10^ndash6when bubble has 12 x 10^-6 rod has 2 x 10^-6 a total of 32 x 10^-6 n07 q4c

coherent = constant phase difference

Progressive wave = transfer of energy as a result of oscillations vibrations of a particles

Nrsquo091 Q5c for diffraction and interference

State what is meant by resonance

1 large maximum amplitude of vibration B12 when impressed frequency equals natural frequency of vibration B1

State and briefly explain a situation in which resonance should be avoided

1 eg metal panels on machinery vibrate oscillate (M1)motor in machine impresses frequency on panel (A1)

2 eg car suspension system vibrates oscillates (M1)going over bumps would give large amplitude vibrations (A1)

Damping

1 either loss of energy (from the system) or amplitude decreases or additional force acting (on the mass)

2 either continuousgradual loss or force always opposing motion

it is the reduction in amplitude due to friction

Resonance

HarmfulThe operation of the engine of a vehicle causes a periodic force on the parts of the vehicle which can cause them to resonate For example at particular frequencies of rotation of the engine the mirrors may resonate To prevent excessive vibration the mountings of the mirrors provide damping

UsefulMusical instruments rely on resonance to amplify the sound producedThe sound from a tuning fork is louder when it is held over a tube of just the right length so that the column of air resonates

Radian- angle (subtended) at centre of circle (by) arc equal in length to radius

Oscillations to-and-fro backward and forward motion (between two limits)

Free oscillations no energy loss or gain no external force acting constant energy constant amplitude

Potential energy of the body ability to do work as a result of the positionshape etc of an object

Speed of the stationary wave

wave is reflected at end at P B1either incident and reflected waves interfereor two waves travelling in opposite directions interfere M1speed is the speed of incident or reflected wave one of these waves A1

Features of a stationary wave that distinguishes it from a progressive wave

no energy transfer amplitude varies along its lengthnodes and antinodes neighbouring points (in inter-nodal loop) vibrate in phase

would break) and this can only be such when the area of bubble is its maximum(max) area of cross-section = (32 ndash 20) times 10ndash6= 12 times 10^ndash6when bubble has 12 x 10^-6 rod has 2 x 10^-6 a total of 32 x 10^-6 n07 q4c

coherent = constant phase difference

Progressive wave = transfer of energy as a result of oscillations vibrations of a particles

Nrsquo091 Q5c for diffraction and interference

State what is meant by resonance

1 large maximum amplitude of vibration B12 when impressed frequency equals natural frequency of vibration B1

State and briefly explain a situation in which resonance should be avoided

1 eg metal panels on machinery vibrate oscillate (M1)motor in machine impresses frequency on panel (A1)

2 eg car suspension system vibrates oscillates (M1)going over bumps would give large amplitude vibrations (A1)

Damping

1 either loss of energy (from the system) or amplitude decreases or additional force acting (on the mass)

2 either continuousgradual loss or force always opposing motion

it is the reduction in amplitude due to friction

Resonance

HarmfulThe operation of the engine of a vehicle causes a periodic force on the parts of the vehicle which can cause them to resonate For example at particular frequencies of rotation of the engine the mirrors may resonate To prevent excessive vibration the mountings of the mirrors provide damping

UsefulMusical instruments rely on resonance to amplify the sound producedThe sound from a tuning fork is louder when it is held over a tube of just the right length so that the column of air resonates

Radian- angle (subtended) at centre of circle (by) arc equal in length to radius

Oscillations to-and-fro backward and forward motion (between two limits)

Free oscillations no energy loss or gain no external force acting constant energy constant amplitude

Potential energy of the body ability to do work as a result of the positionshape etc of an object

Speed of the stationary wave

wave is reflected at end at P B1either incident and reflected waves interfereor two waves travelling in opposite directions interfere M1speed is the speed of incident or reflected wave one of these waves A1

Features of a stationary wave that distinguishes it from a progressive wave

no energy transfer amplitude varies along its lengthnodes and antinodes neighbouring points (in inter-nodal loop) vibrate in phase

Oscillations to-and-fro backward and forward motion (between two limits)

Free oscillations no energy loss or gain no external force acting constant energy constant amplitude

Potential energy of the body ability to do work as a result of the positionshape etc of an object

Speed of the stationary wave

wave is reflected at end at P B1either incident and reflected waves interfereor two waves travelling in opposite directions interfere M1speed is the speed of incident or reflected wave one of these waves A1

Features of a stationary wave that distinguishes it from a progressive wave

no energy transfer amplitude varies along its lengthnodes and antinodes neighbouring points (in inter-nodal loop) vibrate in phase