Ib Sl Physics 11 Topic4

1. Provide examples of oscillations.

1. boiling water

2. walking

3. static object

1. mass on spring(eg. bungeejumping)2. pendulum(eg. swing)3. object bobbing in water(eg. buoy,boat)4. vibrating cantilever(eg.diving board)5. earthquake6. bouncing ball7. musical instruments(eg. strings, percussion, brass, woodwinds,vocal chords)8. heartbeat

Oscillations refer to the repetitive back and forth movement around a central point. Boiling water, walking, and static objects do not demonstrate oscillatory motion as described in the correct examples.

Explanation

Oscillations refer to the repetitive back and forth movement around a central point. Boiling water, walking, and static objects do not demonstrate oscillatory motion as described in the correct examples.

2. DESCRIBE THE INTERCHANGE BETWEEN KINETIC ENERGY AND POTENTIAL ENERGY DURING SHM.

The interchange between kinetic energy and potential energy remains constant during SHM.

Kinetic energy is always zero during SHM.

Potential energy is highest at the top of the swing during SHM.

Kinetic EnergyThe kinetic energy is a maximum when the bob is travelling fastest; this is at the bottom of the swing. At the top of the swing, thebob is stationary, so the KE is zero.Potential EnergyThe potential energy is a minimum when thebob is at its lowest point; we take this to be zero. At the top of the swing, the potential energy is a maximum value.Total EnergyIf no energy is lost then the total energy is aconstant value.When the bob is swinging, the energy continually changes between kinetic and potential.

During Simple Harmonic Motion (SHM), the interchange between kinetic energy and potential energy is not constant, kinetic energy is not always zero, and potential energy can be highest at the top of the swing.

Explanation

During Simple Harmonic Motion (SHM), the interchange between kinetic energy and potential energy is not constant, kinetic energy is not always zero, and potential energy can be highest at the top of the swing.

3. State what is meant by damping.

A. Damping: a force that increases the energy of a system through motion.

B. Damping: a force that acts to stabilize the oscillations in a system.

C. Damping: a force that has no impact on the energy or amplitude of a system.

Damping: a dissipative force acts on a system in the opposite direction of motion of the oscillating particle
Effect of damping: system loses energy and amplitude

Damping refers to a dissipative force that reduces the energy and amplitude of a system, in contrast to the incorrect options provided.

Explanation

Damping refers to a dissipative force that reduces the energy and amplitude of a system, in contrast to the incorrect options provided.

4. What are examples of damped oscillations?

Heat damping: where temperature fluctuations dampen the oscillations

Light damping (under-damping): small resistive force so only a small percentage of energy is removed each cycle - period is not affected - can take many cycles for oscillations to die out (eg: car shock absorbers)
Critical damping : intermediate resistive force so time taken for object to return to mean position is minimum - minimal or no "overshoot" (eg: electric meters with pointers, automatic door closers)
Heavy damping (over damping): large resistive force - can completely prevent any oscillations from taking place - takes a long time for object to return to mean position (eg. oscillations ini viscous fluid)

Sound damping: where sound waves dampen the oscillations

Scent damping: where odor molecules affect the oscillations

The correct answer provides examples of damped oscillations with varying levels of damping. Light damping, critical damping, and heavy damping each have distinct characteristics in how they affect the oscillations of a system. Heat, scent, and sound are not typically associated with damped oscillations.

Explanation

The correct answer provides examples of damped oscillations with varying levels of damping. Light damping, critical damping, and heavy damping each have distinct characteristics in how they affect the oscillations of a system. Heat, scent, and sound are not typically associated with damped oscillations.

5. State the meaning of natural frequency and forced oscillations.

The natural frequency of vibration refers to the random vibrations that occur in a system without any external influence. Forced oscillations are the vibrations that happen when the system is in equilibrium.

Natural frequency occurs when a system is in equilibrium without any movement. Forced oscillations are the vibrations that occur when a system is displaced from equilibrium.

Natural frequency is the frequency at which a system oscillates when a driving force is applied to it. Forced oscillations are the vibrations that occur naturally in a system without any external force.

Natural frequency of vibration: when a system is displaced from equilibrium and allowed to oscillate freely, it will do so at its natural frequency of vibration
Forced oscillations : a system may be forced to oscillate at any given frequency by an outside driving force that is applied to it

The correct answer explains the concepts of natural frequency and forced oscillations accurately, while the incorrect answers provide misleading or incorrect definitions that do not align with the actual meanings.

Explanation

The correct answer explains the concepts of natural frequency and forced oscillations accurately, while the incorrect answers provide misleading or incorrect definitions that do not align with the actual meanings.

6. Describe graphically the variation of the amplitude of a vibrating object when the forced frequency is close to its natural frequency of the object.

A scatter plot showing an increase in amplitude

See picture

A bar graph depicting a decrease in amplitude

A line graph showing a constant amplitude

The correct answer requires a visual representation to accurately describe the variation of amplitude, making the other options incorrect.

Explanation

The correct answer requires a visual representation to accurately describe the variation of amplitude, making the other options incorrect.

7. What is meant by resonance?

Resonance: a transfer of energy in which a system is subject to an oscillating force that matches the natural frequency of the system resulting in a large amplitude of vibration

Resonance is the process of converting sound waves into electrical signals.

Resonance is the ability of an object to float on water.

Resonance is defined as the absorption of light by an object.

Resonance specifically involves the transfer of energy due to oscillating forces matching the natural frequency of a system, leading to significant vibration amplitudes.

Explanation

Resonance specifically involves the transfer of energy due to oscillating forces matching the natural frequency of a system, leading to significant vibration amplitudes.

8. DESCRIBE EXAMPLES OF RESONANCE WHERE THE EFFECT IS USEFUL AND WHERE IT SHOULD BE AVOIDED.

Useful resonance-electricity, turning a radio : the natural frequency of the radio circuit is made equal to the incoming electromagnetic wave the electrons will oscillate with the incoming electromagnetic wave. this is turned into sound, through a speaker
-microwave ovens : microwaves are produced at the same frequency as the natural frequency of water molecules water molecules absorb the energy from the microwaves and transfer their energy to the food in the form of thermal energy
Harmful resonance-driving force at resonance increases the oscillations, sometimes this is unwanted-bridges can be destroyed as the wind (driving force) is at the same as the natural frequency. The bridge vibrated and shook itself apart-tower blocks, the same effect as the bridge the wind, or earthquakes, can cause vibrations to destroy the building

Resonance in earthquake-proof buildings.

Resonance in musical instruments like guitars.

Resonance in car engines.

The incorrect answers do not accurately represent examples of useful or harmful resonance as outlined in the correct answer.

Explanation

The incorrect answers do not accurately represent examples of useful or harmful resonance as outlined in the correct answer.

9. DESCRIBE A WAVE PULSE AND A CONTINUOUS PROGRESSIVE (TRAVELING) WAVE.

Both a wave pulse and a continuous progressive wave involve the net motion of the medium as the wave passes through it.

A wave pulse consists of multiple oscillations occurring simultaneously, while a continuous progressive wave has a single oscillation.

Pulse - single oscillation or disturbance
continuous traveling wave - succession of oscillations (series of periodic pulses)
both pulse and traveling waves : there is a transfer energy though there is no net motion of the medium through which the wave passes

A wave pulse is a continuous wave that travels in a straight line, while a continuous progressive wave moves in a circular pattern.

A wave pulse and a continuous progressive wave have distinct characteristics, including the number of oscillations, motion pattern, and energy transfer. It is important to differentiate between the two types of waves to understand their behavior and properties correctly.

Explanation

A wave pulse and a continuous progressive wave have distinct characteristics, including the number of oscillations, motion pattern, and energy transfer. It is important to differentiate between the two types of waves to understand their behavior and properties correctly.

10. How do progressive (traveling) waves transfer energy?

Progressive (traveling) waves transfer energy.

Progressive (traveling) waves transfer matter.

Progressive (traveling) waves do not transfer energy.

Progressive (traveling) waves transfer sound.

Progressive (traveling) waves are a type of mechanical wave that moves through a medium and transfers energy without displacing matter from one point to another. It is not physical matter that is transferred like in the case of matter waves, and they are separate from sound waves which are a different type of wave that carries sound energy.

Explanation

Progressive (traveling) waves are a type of mechanical wave that moves through a medium and transfers energy without displacing matter from one point to another. It is not physical matter that is transferred like in the case of matter waves, and they are separate from sound waves which are a different type of wave that carries sound energy.

11. DESCRIBE AND GIVE EXAMPLES OF TRANSVERSE AND LONGITUDINAL WAVES.

Both transverse and longitudinal waves travel at the same speed and have similar characteristics.

A transverse wave : is one in which the direction of the oscillation of the particles of the medium is perpendicular to the direction of travel of the wave ( the energy).
Examples: light, violin and guitar strings, ropes, earthquake S waves
A longitudinal wave : is one in which the direction of the oscillation of the particles of the medium is parallel to the direction of the oscillation of the particles of the medium is parallel to the direction of travel of the wave (the energy).
Examples: sound, earthquake P waves

A transverse wave is one in which the direction of the oscillation of the particles is parallel to the direction of travel of the wave. Examples: sound, earthquake P waves.

A longitudinal wave is one in which the direction of the oscillation of the particles is perpendicular to the direction of travel of the wave. Examples: light, violin and guitar strings.

Transverse and longitudinal waves exhibit distinct characteristics in terms of the direction of oscillation of particles and the examples associated with each type. It is important to understand this difference to accurately identify and describe these two types of waves.

Explanation

Transverse and longitudinal waves exhibit distinct characteristics in terms of the direction of oscillation of particles and the examples associated with each type. It is important to understand this difference to accurately identify and describe these two types of waves.

12. DESCRIBE WAVES IN TWO DIMENSIONS INCLUDING CONCEPTS OF WAVEFRONTS AND RAYS.

Wavefronts and rays are not related to each other in the study of waves.

Wavefront : line (or arc) joining neighboring points that have the same phase or displacement
Ray : line indicating direction of wave motion (direction of energy transfer). Rays are perpendicular to wave fronts.

A wavefront is a point where the wave reaches its maximum amplitude. A ray is a line connecting two wavefronts.

A wavefront is the highest point of a wave. A ray is the lowest point of a wave.

In two-dimensional wave analysis, wavefronts are not points but lines connecting points with the same phase, while rays denote the direction of wave motion perpendicular to the wavefronts.

Explanation

In two-dimensional wave analysis, wavefronts are not points but lines connecting points with the same phase, while rays denote the direction of wave motion perpendicular to the wavefronts.

13. DESCRIBE THE TERMS CREST, THROUGH, COMPRESSION AND RAREFACTION.

Crest : points at maximum height of the waveThrough : points at the lowest part of the waveCompression : region where particles of medium are close togetherRarefaction : region where particles of medium are far apart

Crest: points at maximum height of the wave Through: points at the highest part of the wave Compression: region where particles of medium are far apart Rarefaction: region where particles of medium are close together

Crest: points at the middle of the wave Through: points at the highest part of the wave Compression: region where particles of medium are close together Rarefaction: region where particles of medium are far apart

Crest: points at lowest part of the wave Through: points at the highest part of the wave Compression: region where particles of medium are far apart Rarefaction: region where particles of medium are close together

The correct descriptions of crest, through, compression, and rarefaction in relation to waves.

Explanation

The correct descriptions of crest, through, compression, and rarefaction in relation to waves.

14. DEFINE THE TERMS DISPLACEMENT, AMPLITUDE, FREQUENCY, PERIOD, WAVELENGTH, WAVE SPEED AND INTENSITY.

Displacement (x, meters) - distance in particular direction of a particle from its mean position
amplitude (A or x0, meters) - maximum displacement from the mean position
period (T, seconds) - time taken for one complete oscillation / time for one complete wave (cycle) to pass a given point
frequency (f, Hertz) - number of oscillations that take place per unit time
wavelength - shortest distance along the wave between two points that are in phase
wave speed: the speed with which energy is carried in the medium by the wave
intensity - power received per unit area

Speed (S, meters per second) - measure of how fast an object is moving; Volume (V, cubic meters) - amount of space occupied by an object; Force (F, Newtons) - push or pull exerted on an object

The correct answers provided define specific terms related to waves and oscillation, while the incorrect answers are unrelated terms in physics.

Explanation

The correct answers provided define specific terms related to waves and oscillation, while the incorrect answers are unrelated terms in physics.

15. DRAW AND EXPLAIN DISPLACEMENT - TIME AND DISPLACEMENT - DISTANCE GRAPHS FOR TRANSVERSE AND LONGITUDINAL WAVES .

Draw and explain speed-time and speed-distance graphs for transverse and longitudinal waves

Discuss the reflection and refraction of transverse and longitudinal waves in different mediums

Describe the relationship between wavelength and frequency in transverse and longitudinal waves

See picture

16. State the fact that all electromagnetic waves travel at the same speed in free space and know the orders of magnitude of the wavelengths of the principal radiations in the electromagnetic spectrum.

Wavelengths of electromagnetic waves vary depending on the type of radiation.

Electromagnetic waves travel at different speeds in free space.

The speed of electromagnetic waves in free space depends on the frequency.

See picture

In the electromagnetic spectrum, all waves travel at the speed of light in free space, which is approximately 3 x 10^8 meters per second. The wavelengths of the principal radiations in the electromagnetic spectrum vary widely, ranging from meters to nanometers.

Explanation

In the electromagnetic spectrum, all waves travel at the speed of light in free space, which is approximately 3 x 10^8 meters per second. The wavelengths of the principal radiations in the electromagnetic spectrum vary widely, ranging from meters to nanometers.

17. DESCRIBE THE REFLECTION AND TRANSMISSION OF WAVES AT A BOUNDARY BETWEEN TWO MEDIA.

Reflection: the angle of incidence is opposite to the angle of reflection when both angles are measured with respect to the normal line.

Law of reflection : the angle of incidence is equal to the angle of reflection when both angles are measured with respect to the normal line ( and the incident ray, reflected ray and normal all lie in the same plane).
refraction : the changes in direction of a wave (due to change in speed) when it crosses a boundary between two different media at an angle
transmission : when a wave incident on the boundary between two media and passes from one medium to another, some energy will be absorbed and reflected at the boundary

Transmission: all the energy of the wave is absorbed at the boundary and no wave passes through to the other medium.

Refraction: the speed of the wave remains constant when it crosses a boundary between two different media at an angle.

The correct answer explains the correct principles of reflection and transmission at a boundary between two media. The incorrect answers provide misconceptions or inaccuracies regarding these principles.

Explanation

The correct answer explains the correct principles of reflection and transmission at a boundary between two media. The incorrect answers provide misconceptions or inaccuracies regarding these principles.

18. State and apply Snell's Law.

The ratio of the secant of the angle of incidence to the secant of the angle of refraction is a constant for a given frequency.

The ratio of the cosine of the angle of incidence to the cosine of the angle of refraction is a constant for a given frequency.

Snell's law: the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for a given frequency

The ratio of the tangent of the angle of incidence to the tangent of the angle of refraction is a constant for a given frequency.

Snell's Law is a principle in optics that describes the relationship between the angles of incidence and refraction when a wave passes through a boundary between two different media. It is based on the change in speed of the wave as it moves from one medium to another, causing it to bend. The correct answer states the accurate description of Snell's Law, which highlights the constant ratio of the sines of the angles involved.

Explanation

Snell's Law is a principle in optics that describes the relationship between the angles of incidence and refraction when a wave passes through a boundary between two different media. It is based on the change in speed of the wave as it moves from one medium to another, causing it to bend. The correct answer states the accurate description of Snell's Law, which highlights the constant ratio of the sines of the angles involved.

19. Explain and discuss qualitatively the diffraction of waves by apertures and obstacles.

Diffraction only occurs when the wavelength is much smaller than the obstacle.

Diffraction happens only when the wavelength is larger than the obstacle size.

Most of the energy associated with the waves is propagated in the same direction as the incident waves
when the wavelength is small compared to the aperture, the amount of diffraction is minimal
when the wavelength is comparable to the opening, then diffraction takes place
diffraction also takes place when a wave moves passed an obstacle
if the wavelength is much smaller than the obstacle, little diffraction takes place
If the wavelength is comparable to the obstacle size, then diffraction takes place

Diffraction takes place when the wavelength is small compared to the aperture, but not when it is comparable to the opening.

20. What is an example of diffraction?

D diffraction is the spreading of waves due to passing through an obstacle.

A diffraction is the bending of light as it travels from one medium to another.

C diffraction is the process of focusing light rays to form an image.

Diffraction: spreading of waves when they pass through an opening, slit, an aperture, or round an obstacle. they spread out to some extend into a region not in the path of the waves.
examples 1. shadows - the edges of a shadow's figure are not sharp, nor are they well - defined. The farther the object is, the more blurred the shadow becomes due to diffraction
2. Ripple tanks - spreading out of a wave makes it go through an aperture or encounter an object
3. shining a laser light through a narrow slit - diffraction a t the lit produces a pattern on the screen that consists of illumination separated by dark areas. - Each point is acting a s a secondary source, and it pattern results from the interference of waves.

B diffraction is the reflection of light rays off a smooth surface.

Diffraction specifically refers to the spreading of waves when they encounter an opening or obstacle, not the bending of light at interfaces, reflection off surfaces, or the focusing of light rays to form an image.

Explanation

Diffraction specifically refers to the spreading of waves when they encounter an opening or obstacle, not the bending of light at interfaces, reflection off surfaces, or the focusing of light rays to form an image.

21. State the principle of superposition and explain what is meant by constructive and destructive interference.

Superposition is when waves pass through different mediums.

Constructive interference is the interference in which the waves do not combine to form a resultant.

Superposition : when two waves pass the same point at the same time, their displacements are added together to calculate the resultant displacement.
Interference: superposition of coherent sources resulting in an interference pattern.
constructive interference: interference in which the resultant is reinforced
destructive interference: interference in which the resultant is cancelled.

Interference is the non-superposition of coherent sources resulting in no interference pattern.

Superposition is the fundamental principle in wave theory. Constructive and destructive interference refer to how waves combine when they meet. Constructive interference leads to reinforcement of the waves, while destructive interference causes cancellation.

Explanation

Superposition is the fundamental principle in wave theory. Constructive and destructive interference refer to how waves combine when they meet. Constructive interference leads to reinforcement of the waves, while destructive interference causes cancellation.

22. State and apply the conditions for constructive and destructive interference in terms of path difference and phase difference.

Phase difference plays a minor role in interference.

Constructive interference occurs when path difference is a multiple of the wavelength.

Path difference determines interference type.

See picture