Physics SS 2 Curriculum Guides – Types of Waves – Sound and Light Waves, Human Eyes, Properties of Waves, Production and Propagation of Waves and Applications of Waves

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. classify waves into longitudinal and transverse waves by using mode of vibration and direction of propagation.

2. write down and explain the terms in the wave equation.

FOCUS LESSONS

1. Longitudinal waves.

2. Transverse waves

3. Wave equation Y = A sin (wt – 2πx ∕ λ).

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. provide rope and slinky to demonstrate transverse and longitudinal waves.

2. explain the wave equation Y = A sin (wt – 2πx ∕ λ) and the various terms.

STUDENT’S ACTIVITIES

The students use the rope and the slinky to demonstrate transverse and longitudinal waves.

LESSON EVALUATION

Students to explain the terms in the wave equation and solve simple problems using the equation.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. identify vibrating sources when sound is produced

2. distinguish between noise and music, intensity and loudness and pitch and frequency as applied to sound.

3. explain forced vibration and explain how it is used to amplify a sound.

4. use the relationship, v = fλ in solving numerical problems.

5. explain the formation of standing waves and produce these waves in stretching strings.

6. use resonance tube to determine the velocity of sound in air.

FOCUS LESSONS

1. Sources of sound

2. Transmission of sound

3. Noise and music

4. Pitch, loudness and quality

5. Forced vibration – resonance and harmonics and overtones

6. Speed of sound in solid, liquid and air

7. Velocity of sound – its measurement

8. Stationary waves

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. demonstrates that sound does not travel in a vacuum by using the electric bell enclosed in a jar.

2. demonstrates forced vibration with the resonance boxes and sonometer.

3. demonstrates the determination of the speed of sound in air by using the resonance tube method or the sonometer.

STUDENT’S ACTIVITIES

The students,

1. use resonance boxes and sonometer to illustrate forced vibration.

2. determine the speed of sound in air by using the resonance tube method or the sonometer.

LESSON EVALUATION

Students to,

1. distinguish between noise and music.

2. intensity and loudness, pitch and frequency.

3. explain forced vibration and resonance.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

INSTRUCTIONAL MATERIALS

Ray box, plane mirror

1. Optical pin, plane mirror ruler, drawing board

2. Ray box, concave mirror, screen, meter rule, converging lens

3. Ray box with illuminated object, rectangular glass block

4. Optical pin, rectangular glass block, drawing board

5. Drawing on chart board and using semicircular prism

6. Optical pin, drawing board, paper, incident angles between 5o and 25o using triangular prism

7. Triangular prism using incident angles between 30o and 70o, optical pins, drawing board and paper

8. Triangular prism, source of light, screen

9. Pictures/charts or film show on sun’s radiation on the earth

10. Ray box, convex lens, screen, meter rule.

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. list some light sources they come across in everyday life.

2. determine the angle of reflection for a given angle of incidence.

3. draw ray diagrams to show the formation of images by plane and curved mirrors.

4. explain some practical applications of plane and curved mirrors.

5. explain how the direction of light changes as it travels from one medium into the other.

6. measure angles of incidence and refraction and hence deduce a value for the refractive index of a given material.

7. explain the meaning of critical angle and total internal reflection stating the conditions under which they occur.

8. establish the relationship between critical angle and refractive index, and apply it to the solution of simple problems.

9. trace light rays through a triangular prism and obtain graphically the value of the angle of minimum deviation.

10. obtain the spectrum of white light.

11. describe the spectra of solar energy received by earth.

12. obtain images due to light rays through converging and diverging lenses using ray tracks and ray tracing method.

13. use the lens formula to solve numerical problems on lenses.

FOCUS LESSONS

1. Sources of light

2. Light and matter

3. Transmission of light

4. Reflection of light at plane mirror surface and curved mirrors

5. Formation of images by plane mirrors and curved mirrors

6. Laws of reflection

7. Parabolic mirror as application of reflection of light on curved surfaces

8. Refraction of light through rectangular glass block and triangular prism

9. Laws of refraction

10. Critical angle and total internal reflection

11. Angle of deviation

12. Dispersion of white light

13. Sun’s energy and the radiation to the earth

14. Refraction of light through converging lenses and diverging lenses

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. leads a class discussion on the laws of reflection of light waves.

2. demonstrates that the incident ray, the normal and the reflected ray all lie on the same plane.

3. demonstrates the laws of refraction of light waves.

4. demonstrates the relationship between u, v, and f in the mirror equation.

5. demonstrates the formation of images at different points on the principal axis of mirrors and buses.

6. demonstrates how to obtain critical angle and total internal reflection; and assist students to relate them to the refractive index of glass or a medium.

7. demonstrates the dispersion of light by a triangular glass prism.

8. shows film or pictures/charts on the effects of the sun’s radiation on the earth.

9. demonstrates the relationship between object distance, image distance and the focal length of a lens.

10 provides worked examples on problems on mirrors and lenses both graphically and analytically.

STUDENT’S ACTIVITIES

The students,

1. show the laws of reflection by using a ray box and a plane mirror.

2. locate the image of an object behind a plane mirror.

3. show by experiment that the incident ray, the normal and the reflected ray all lie on the same plane.

4. locate image position by using curved mirror.

5. investigate the relationship between u, v, and f – the mirror equation.

6. show formation of images at different points on the principal axis of mirrors and lenses.

7. use the ray box to show the refraction of light through a rectangular glass block.

8. vary the angles of incidence and obtain their corresponding angles of refraction and use this to establish Snell’s law.

9. show how critical angle and total internal reflection are obtained and relate them to the refractive index of glass or a medium.

10. use the experiment with the triangular prism to obtain minimum angle of deviation and show its relationship with the refractive index of glass.

11. view the pictures/charts or film show on the effects of the sun’s radiation on the earth.

12. use the ray box to show the relationship between object distance, image distance and the focal length of a lens.

13. solve problems on mirrors and lenses both graphically and analytically.

LESSON EVALUATION

Students to,

1. state some applications of plane and curved mirrors.

2. solve simple problems on mirror formula.

3. explain refraction of light through rectangular glass block and triangular glass prism.

4. explain critical angle and total internal reflection and solve simple problems on them.

5. explain sun’s radiation to the earth.

6. solve simple problems applying the lens formula.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

INSTRUCTIONAL MATERIALS

A model of the human eye, camera (box) and standard camera

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. explain the role played by some parts of the eye in the formation of image on the retina.

2. compare and contrast the eye and the camera.

3. state the defects of the eye and their causes.

4. identify the type of lenses for correcting the various defects of the eye.

FOCUS LESSONS

1. The human eye

2. Comparison of eye and camera

3. Defects of vision

4. Correction of defects.

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. provides pictures/model/charts of the human eye showing its various parts.

2. leads students to discuss the functions of the different parts of the eye.

3. leads students to discuss the similarities and dissimilarities of the parts of the eye with those of the camera.

STUDENT’S ACTIVITIES

The students study the human eye and compare its structure and function with the simple camera.

LESSON EVALUATION

Students to,

1. state the similarities and differences between the human eye and a camera.

2. explain the defects of the eye and its corrections.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

INSTRUCTIONAL MATERIALS

1. Ripple tank or wide transparent plastic bowl, thin horizontal bar ruler, water

2. Ray box, plane mirror or concave mirror, screen

3. Source of sound, reflector, hard surface

4. Source of heat, shiny surface or mirror, match stick or thermometer

5. Optical pin or big needle or office pin, glass block and triangular prism, drawing board

6. Ray box, convex lens, screen, metre rule.

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. produce plane and circular waves using ripple tank.

2. demonstrate the reflection of sound.

3. demonstrate stationery waves.

4. demonstrate reflection of heat radiation.

5. demonstrate refraction of water waves and sounds.

FOCUS LESSONS

1. Reflection of waves – laws of reflection

2. Superposition of waves – two waves in the same direction (progressive wave) and two waves in opposite direction (standing or stationary waves)

3. Refraction of waves – laws of refraction

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. sets up the ripple tank to produce various waves.

2. demonstrates reflection of sound from wrist watch by a reflector and  reflection of heat energy by a polished surface.

3. leads the class to discuss properties of waves.

STUDENT’S ACTIVITIES

The students,

1. use the ripple tank to produce wave forms. Students should draw the various patterns formed when waves are reflected.

2. use the ray-box to trace incident and reflected rays of light.

3. do experiments on refraction of light through glass prism and lenses.

LESSON EVALUATION

Students to explain terms: reflection, refraction and superposition of waves.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

INSTRUCTIONAL MATERIALS

1. Rope or slinky coil, piece of cloth tied on a part of the rope or slinky coil.

2. Ripple tank or wide transparent bowl, water

3. Stop watch or clock, rope or slinky coil

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. generate mechanical waves.

2. state the important characteristics of waves.

3. produce circular and plane waves using a ripple tank.

4. generate and demonstrate longitudinal and transverse waves using suitable materials.

5. identify the crest, through amplitude wave length and points in phase on a given sine wave form.

6. derive and use the relationship between wave velocity, frequency and wavelength.

7. identify light as electromagnetic waves.

FOCUS LESSONS

1. Production of mechanical waves.

2. Pulsating system – energy transmitted with definite speed, frequency and wavelength

3. Wave form – description and graphical representation.

4. Mathematical relationships among f, λ, T and v.

5. Sound and light as wave phenomena.

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. provides the materials for generating mechanical waves.

2. demonstrates the use of ropes and slinky to generate mechanical waves.

3. sets up the ripple tank and demonstrate how it is used to generate various waves.

4. gives simple problem on the use of the wave equation v – fλ.

STUDENT’S ACTIVITIES

The students,

1. generate mechanical waves using ropes and springs (slinky)

2. uses the ripple tank to show water waves

3. demonstrate energy propagation by waves using water waves.

4. determine the speed of a wave by using the waves generated in a rope or slinky (spring).

5. draw a graphical representation of transverse and longitudinal waves

6. solve problems using the wave equation v = fλ

LESSON EVALUATION

Students to,

1. distinguish between wave motion and vibration of particles.

2. identify forms of waves.

3. state the characteristics of waves.

4. solve simple problems using the equation v = fλ.

THEME – WAVES, MOTION WITHOUT MATERIAL TRANSFER

INSTRUCTIONAL MATERIALS

1. The local musical instruments falling into the classes of wind, stringed and percussion instruments

2. Hearing aids device

LEARNING OBJECTIVES

By the end of the lesson, students should be able to:

1. classify musical instrument into wind instruments, stringed instruments and percussion instruments.

2. explain the physical principles involved in the use of wind, sting and percussion instruments.

3. use the reflection of sound to explain echoes.

4. give an application of echoes.

5. explain the function of hearing aids.

FOCUS LESSONS

1. Wind instruments:

• clarinet
• flute
• saxophone
• trumpet

2. Stringed instruments:

• guitar
• sonometer
• piano

3. Percussion instruments:

• drum
• bell
• the talking drum

4. Echoes and their applications

5. Hearing aids.

LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. arranges for local musical instruments to be brought to class for students to see, identify and discuss their function and importance.

2. shows films or lead discussion on the use of echoes in oil exploration, determination of sea-beds and in sub-marine.

3. provides a hearing aids or its picture/chart for students to examine and identify its parts.

4. invites an expert to speak on application of sound in health and/or oil industry.

STUDENT’S ACTIVITIES

The students,

1. identify the local musical instruments in class and discuss their importance in the production of music.

2. watch films or discuss, using other aids, the use of echoes in:

• oil exploration
• determination of sea-beds
• sub-marine.

3. examine a hearing aid device and identify its parts.

LESSON EVALUATION

Students to,

1. calculate speed of sound, time for the sound to travel, depth of sea-beds, distance of cliff, or high wall from an observer.

2. students to classify musical instruments.

3. list some functions of hearing aid.