Mechanics and Thermal Physics

Moments and Equilibrium - Centre of gravity of regular objects
Moments and Equilibrium - Centre of gravity of triangles
Moments and Equilibrium - Centre of gravity of irregular objects

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

- Define centre of gravity
- Determine the C.O.G of regular shaped objects (square, rectangle, circle)
- Relate centre of gravity to balancing objects on fingertips

- Determine C.O.G of triangular objects using medians
- Locate C.O.G at intersection of medians
- Apply knowledge of C.O.G to understanding stability of triangular structures

In groups, learners are guided to:
- Use balancing method to find C.O.G of regular cut-outs
- Use geometrical construction (diagonals) to locate C.O.G
- Compare results from both methods
- Cut out triangular shapes from cardboard
- Construct medians and mark intersection point
- Verify C.O.G by balancing on pencil tip

Where is the centre of gravity of a square located?
How do we find the centre of gravity of a triangle?

- Spotlight Physics Learner's Book pg. 78
- Cut-out shapes (square, rectangle, circle)
- Pencil for balancing
- Ruler
- Spotlight Physics Learner's Book pg. 80
- Triangular cut-outs
- Ruler
- Pencil
- Marker
- Spotlight Physics Learner's Book pg. 81
- Irregular cardboard shapes
- String and small weight (plumb line)
- Stand and clamp

- Practical assessment - Observation - Oral questions
- Practical assessment - Written questions - Observation

Mechanics and Thermal Physics

Moments and Equilibrium - Stable equilibrium
Moments and Equilibrium - Unstable and neutral equilibrium

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

- Define stable equilibrium
- Demonstrate stable equilibrium using cone on its base
- Connect stable equilibrium to design of racing cars with low C.O.G

In groups, learners are guided to:
- Place cone on its wide base and push slightly
- Observe return to original position
- Discuss characteristics of stable equilibrium

Why does a cone on its base return to its original position when pushed?

- Spotlight Physics Learner's Book pg. 83
- Cone-shaped objects
- Flat surface
- Spotlight Physics Learner's Book pg. 84
- Spherical ball

- Practical assessment - Oral questions - Written assignments

Mechanics and Thermal Physics

Moments and Equilibrium - Factors affecting stability
Moments and Equilibrium - Turning effect of a force

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

- Investigate effect of base area on stability
- Investigate effect of position of C.O.G on stability
- Connect stability factors to why buses have luggage compartments underneath

In groups, learners are guided to:
- Compare stability of bottles with different amounts of sand
- Compare stability of books resting on different surfaces
- Discuss how to increase stability of objects

How does the position of centre of gravity affect stability?

- Spotlight Physics Learner's Book pg. 85
- Plastic bottles
- Sand
- Similar books
- Spotlight Physics Learner's Book pg. 89
- Door
- Spring balance
- Ruler

- Practical assessment - Oral questions - Written tests

Mechanics and Thermal Physics

Moments and Equilibrium - Calculating moments
Moments and Equilibrium - Verifying principle of moments

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

- Calculate moment of a force using Moment = Force × perpendicular distance
- State the SI unit of moment
- Apply moment calculations to using spanners to loosen tight bolts

In groups, learners are guided to:
- Apply forces at different distances from pivot
- Calculate moments from experimental data
- Solve numerical problems on moments

How does increasing distance from pivot affect the turning effect?

- Spotlight Physics Learner's Book pg. 90
- Ruler on pivot
- Spring balance
- Known weights
- Metre rule
- Spotlight Physics Learner's Book pg. 91
- Metre rule
- Knife edge pivot
- Known masses
- String

- Written tests - Problem-solving exercises - Practical assessment

Mechanics and Thermal Physics

Moments and Equilibrium - Applications of principle of moments
Moments and Equilibrium - Determining mass using moments

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

- Apply principle of moments to solve problems
- Determine unknown forces using principle of moments
- Use principle of moments to calculate where children should sit on a see-saw to balance

- Determine mass of a metre rule using principle of moments
- Locate C.O.G of a metre rule experimentally
- Apply the method to weighing objects using simple beam balances

In groups, learners are guided to:
- Solve problems involving balanced beams
- Calculate unknown masses and distances
- Discuss applications in beam balances and levers
- Suspend metre rule and find balance point
- Use known mass to determine mass of rule
- Apply principle of moments in calculations

How can we use moments to find an unknown mass?
How can we determine the mass of a ruler using moments?

- Spotlight Physics Learner's Book pg. 92
- Scientific calculators
- Problem sheets
- Beam balance
- Spotlight Physics Learner's Book pg. 93
- Metre rule
- Stand and thread
- Known masses (50g, 100g)

- Written tests - Problem-solving exercises - Oral questions
- Practical assessment - Written tests - Problem-solving

Mechanics and Thermal Physics

Moments and Equilibrium - Parallel forces and two supports

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

- Demonstrate moments about two points of support
- Apply conditions for equilibrium with parallel forces
- Connect parallel forces to how bridges distribute weight across supports

In groups, learners are guided to:
- Set up metre rule supported by two spring balances
- Attach weights at different positions
- Verify sum of upward forces equals sum of downward forces

How are forces distributed in a beam supported at two points?

- Spotlight Physics Learner's Book pg. 94
- Metre rule
- Two spring balances
- Known weights
- Stand

- Practical assessment - Written tests - Observation

Mechanics and Thermal Physics

Moments and Equilibrium - Couple and torque

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

- Define a couple as two equal and opposite parallel forces
- Calculate torque as Force × perpendicular distance between forces
- Connect couples to turning steering wheels and opening bottle caps

In groups, learners are guided to:
- Demonstrate couple using a plank fixed at centre
- Apply equal forces in opposite directions
- Calculate torque from experimental data

Why do we need two hands to turn a steering wheel smoothly?

- Spotlight Physics Learner's Book pg. 97
- Uniform plank with central pivot
- Spring balances
- Steering wheel model

- Practical assessment - Written tests - Oral questions

Mechanics and Thermal Physics

Moments and Equilibrium - Applications and resolution of forces
Energy, Work, Power and Machines - Definition of work
Energy, Work, Power and Machines - Calculating work done

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

- Describe applications of torque and couples
- Resolve forces to find perpendicular components
- Apply moments to real-life situations like using spanners, screwdrivers and bicycle pedalling

In groups, learners are guided to:
- Discuss applications of moments in daily life
- Solve problems involving forces at angles
- Calculate moments when force is not perpendicular

How do we calculate moments when force is applied at an angle?

- Spotlight Physics Learner's Book pg. 100
- Pictures of applications
- Digital resources
- Problem sheets
- Spotlight Physics Learner's Book pg. 105
- Spring balance
- Metre rule
- Various objects
- Spotlight Physics Learner's Book pg. 107
- Known masses
- Stopwatch

- Written tests - Oral questions - Project presentations

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Energy and its forms
Energy, Work, Power and Machines - Definition and calculation of power
Energy, Work, Power and Machines - Kinetic energy
Energy, Work, Power and Machines - Gravitational potential energy

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

- Define energy as ability to do work
- Identify different forms of energy
- Connect energy forms to household appliances like heaters, bulbs and motors

- Define kinetic energy as energy due to motion
- Calculate kinetic energy using KE = ½mv²
- Connect kinetic energy to moving vehicles, athletes and flowing water

In groups, learners are guided to:
- Move objects and discuss energy expended
- Identify forms of energy in various situations
- Discuss energy sources and their uses
- Roll toy car down ramp and calculate its kinetic energy
- Investigate how mass and velocity affect K.E
- Solve problems on kinetic energy

What enables us to do work?
How does speed affect the kinetic energy of a moving object?

- Spotlight Physics Learner's Book pg. 108
- Various objects
- Pictures of energy sources
- Digital resources
- Stopwatch
- Spring balance
- Known masses
- Calculators
- Spotlight Physics Learner's Book pg. 112
- Toy car
- Ramp
- Stopwatch
- Measuring tape
- Beam balance
- Spotlight Physics Learner's Book pg. 114
- Small weights
- Metre rule
- Beam balance
- Stand

- Oral questions - Written assignments - Group discussions
- Practical assessment - Written tests - Problem-solving

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Elastic potential energy
Energy, Work, Power and Machines - Conservation of mechanical energy

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

- Define elastic potential energy
- Demonstrate elastic P.E in stretched materials
- Connect elastic potential energy to catapults, bow and arrow, and car shock absorbers

In groups, learners are guided to:
- Stretch rubber bands and release to propel objects
- Investigate elastic P.E in springs
- Calculate elastic P.E using area under F-e graph

How do stretched materials store energy?

- Spotlight Physics Learner's Book pg. 116
- Rubber bands
- Springs
- Small objects
- Paper balls
- Spotlight Physics Learner's Book pg. 118
- Pendulum bob
- String
- Stand
- Metre rule

- Practical assessment - Observation - Written questions

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Energy transformations

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

- Describe energy transformations in various systems
- Apply conservation of energy to solve problems
- Connect energy transformations to motor vehicles, power stations and home appliances

In groups, learners are guided to:
- Discuss energy changes in falling objects, vehicles, and appliances
- Visit a garage to observe energy transformations in vehicles
- Solve problems using conservation of energy

How is energy transformed in a moving vehicle?

- Spotlight Physics Learner's Book pg. 121
- Digital resources
- Pictures of machines
- Reference books

- Written tests - Oral questions - Project work

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Types of simple machines
Energy, Work, Power and Machines - MA, VR and efficiency

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

- Identify types of simple machines
- Describe applications of levers, pulleys and inclined planes
- Connect simple machines to everyday tools like scissors, wheelbarrows and ramps

In groups, learners are guided to:
- Use digital resources to search for types of simple machines
- Identify simple machines in the environment
- Classify levers into first, second and third class

How do simple machines make work easier?

- Spotlight Physics Learner's Book pg. 124
- Pictures of simple machines
- Examples of levers
- Inclined plane model
- Spotlight Physics Learner's Book pg. 129
- Simple machines
- Spring balance
- Known masses
- Metre rule

- Oral questions - Written assignments - Observation

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Levers
Energy, Work, Power and Machines - Pulleys

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

- Calculate MA and VR of levers
- Apply principle of moments to levers
- Relate lever calculations to using crowbars, scissors and wheelbarrows

- Calculate VR of pulley systems
- Investigate efficiency of pulley systems
- Connect pulley systems to cranes, flagpoles and construction hoists

In groups, learners are guided to:
- Set up different classes of levers
- Calculate MA and VR experimentally
- Solve problems on levers
- Set up single fixed and movable pulleys
- Set up block and tackle system
- Calculate MA, VR and efficiency experimentally

How does the position of the fulcrum affect the mechanical advantage of a lever?
How does the number of pulleys affect the velocity ratio?

- Spotlight Physics Learner's Book pg. 131
- Lever apparatus
- Known masses
- Spring balance
- Metre rule
- Spotlight Physics Learner's Book pg. 131
- Pulleys
- String
- Known masses
- Spring balance
- Stand

- Practical assessment - Written tests - Problem-solving
- Practical assessment - Written tests - Observation

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Inclined plane and screw

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

- Calculate VR of inclined plane as length/height
- Calculate VR of screw using pitch and circumference
- Connect inclined planes to loading ramps and wheelchair access, and screws to car jacks

In groups, learners are guided to:
- Roll objects up inclined plane at different angles
- Calculate VR of inclined plane
- Discuss relationship between screw and inclined plane

How does the angle of inclination affect the effort required?

- Spotlight Physics Learner's Book pg. 134
- Inclined plane
- Screw jack
- Spring balance
- Metre rule

- Practical assessment - Written tests - Problem-solving

Mechanics and Thermal Physics

Energy, Work, Power and Machines - Wheel and axle, gears

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

- Calculate VR of wheel and axle
- Calculate VR of gear systems
- Connect wheel and axle to steering wheels and door knobs, and gears to bicycles and car gearboxes

In groups, learners are guided to:
- Demonstrate wheel and axle operation
- Calculate VR of gear systems with different teeth
- Solve problems on wheel and axle and gears

How do gears change speed and force?

- Spotlight Physics Learner's Book pg. 137
- Wheel and axle model
- Gear wheels
- Bicycle

- Practical assessment - Written tests - Oral questions

Mechanics and Thermal Physics
Waves and Optics

Energy, Work, Power and Machines - Hydraulic machines and applications
Properties of Waves - Rectilinear propagation of waves

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

- Explain working principle of hydraulic machines
- Calculate force multiplication in hydraulic systems
- Connect hydraulic machines to car brakes, car jacks and construction equipment

In groups, learners are guided to:
- Construct simple hydraulic system using syringes
- Calculate force and VR of hydraulic press
- Discuss applications in vehicles and construction
- Identify simple machines in treadmills, elevators and escalators

How do hydraulic machines multiply force?

- Spotlight Physics Learner's Book pg. 139
- Syringes of different sizes
- Tubing
- Water
- Pictures of hydraulic machines
- Spotlight Physics Grade 10 pg. 147
- Torch
- Digital resources

- Practical assessment - Written tests - Project presentations

Waves and Optics

Properties of Waves - Reflection of waves
Properties of Waves - Refraction of waves
Properties of Waves - Diffraction of waves
Properties of Waves - Interference of waves

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

- Explain the meaning of reflection of waves
- Demonstrate reflection of sound waves using a tall building scenario
- Connect reflection to real-life applications like radar systems and car side mirrors

- Explain the meaning of diffraction of waves
- Demonstrate diffraction using a torch and cone-shaped speaker
- Connect diffraction to how we hear sound around corners and obstacles

In groups, learners are guided to:

- Discuss how sound waves bounce off hard surfaces
- Identify applications of reflection in radar, mirrors, and fibre optics
- Use print or non-print media to research reflection applications

- Flash a torch at night towards a wall and observe light spreading
- Use a cone-shaped manila paper as a speaker to demonstrate sound diffraction
- Discuss how sound waves bend around obstacles

Why do we hear echoes near tall buildings?
How can we hear sound around corners?

- Spotlight Physics Grade 10 pg. 148
- Digital resources
- Charts showing reflection
- Spotlight Physics Grade 10 pg. 150
- Glass of water
- Straight object
- Digital resources
- Spotlight Physics Grade 10 pg. 151
- Torch
- Manila paper
- Digital resources
- Spotlight Physics Grade 10 pg. 152
- Two identical speakers
- Audio frequency generator

- Oral questions - Observation - Group presentations
- Oral questions - Observation - Practical demonstration

Waves and Optics

Properties of Waves - Demonstrating rectilinear propagation using ripple tank
Properties of Waves - Demonstrating reflection using ripple tank

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

- Set up a ripple tank to demonstrate wave properties
- Demonstrate rectilinear propagation of waves in a ripple tank
- Connect the formation of bright and dark spots to how water waves behave

In groups, learners are guided to:

- Set up a ripple tank with all accessories
- Observe how crests appear bright and troughs appear dark
- Place two straight rods perpendicular to the vibrating bar and observe wave direction

How do waves move in a straight line?

- Spotlight Physics Grade 10 pg. 154
- Ripple tank and accessories
- Dry cell and cell holder
- White manila paper
- Spotlight Physics Grade 10 pg. 156
- Ripple tank
- Straight metal reflector
- Concave and convex reflectors

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Demonstrating refraction using ripple tank
Properties of Waves - Demonstrating diffraction using ripple tank

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

- Demonstrate refraction of waves using a ripple tank
- Observe changes in wavelength as waves move from deep to shallow water
- Connect wave refraction to how light bends when entering water

In groups, learners are guided to:

- Create a shallow region in the ripple tank using a transparent glass plate
- Produce straight plane waves and observe separation of ripples
- Tilt the glass plate at an acute angle and observe wave bending

Why does the wavelength change when waves move from deep to shallow water?

- Spotlight Physics Grade 10 pg. 158
- Ripple tank
- Transparent glass plate
- White manila paper
- Spotlight Physics Grade 10 pg. 159
- Two straight metal barriers
- Opaque obstacle

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Demonstrating interference using ripple tank

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

- Demonstrate interference of waves using a ripple tank
- Identify constructive and destructive interference patterns
- Relate interference patterns to noise-cancelling headphones and acoustic design

In groups, learners are guided to:

- Fix two spherical balls below the vibrator bar as coherent sources
- Observe dark and bright radial lines showing interference pattern
- Discuss how bright lines show constructive and dark lines show destructive interference

How are interference patterns formed in a ripple tank?

- Spotlight Physics Grade 10 pg. 160
- Ripple tank
- Two spherical balls
- White manila paper

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Production of frequency modulated (FM) waves
Properties of Waves - Detection of frequency modulated (FM) waves

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

- Explain the meaning of frequency modulation
- Describe methods of producing FM waves
- Connect FM to how radio stations broadcast music and news

- Explain how FM waves are detected and demodulated
- Describe applications of FM in various fields
- Relate FM detection to how radios and television sets receive signals

In groups, learners are guided to:

- Use digital devices to research the meaning of FM and its production
- Discuss the difference between FM and AM
- Search for applications of frequency modulation

- Discuss demodulation methods for FM signals
- Research applications of FM in radar systems, medical imaging, and telemetry
- Present findings on FM applications to classmates

How are FM radio signals produced?
How do radios detect and convert FM signals to sound?

- Spotlight Physics Grade 10 pg. 161
- Digital resources
- Physics reference books

- Spotlight Physics Grade 10 pg. 162
- Digital resources
- Radio receiver (demonstration)

- Oral questions - Written assignments - Group presentations
- Oral questions - Written tests - Research presentations

Waves and Optics

Properties of Waves - Formation of stationary waves
Properties of Waves - Factors affecting fundamental frequency of vibrating string

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

- Explain the meaning of stationary waves
- Demonstrate formation of stationary waves using a tuning fork and string
- Connect stationary waves to how guitar strings produce different notes

In groups, learners are guided to:

- Fix a string to a tuning fork prong and pass over a fixed pulley
- Strike the tuning fork and observe nodes and antinodes
- Discuss how incident and reflected waves superimpose to form stationary waves

How are stationary waves formed in a vibrating string?

- Spotlight Physics Grade 10 pg. 163
- Tuning fork
- String
- Mass (weight)
- Fixed pulley system
- Spotlight Physics Grade 10 pg. 164
- Sonometer apparatus
- Weights
- Two wooden wedges

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Modes of vibration in strings

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

- Explain modes of vibration in strings
- Calculate frequencies of harmonics and overtones
- Connect harmonics to the rich sound quality of musical instruments

In groups, learners are guided to:

- Discuss fundamental frequency and how it relates to wavelength
- Calculate first and second overtones using mathematical relationships
- Use the general formula for nth overtone: fn = (n+1)f₀

What are harmonics and overtones in vibrating strings?

- Spotlight Physics Grade 10 pg. 166
- Digital resources
- Charts showing modes of vibration

- Written tests - Oral questions - Problem-solving exercises

Waves and Optics

Properties of Waves - Stationary waves in closed pipes

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

- Investigate variation of sound with length of air column in a closed pipe
- Demonstrate resonance in a closed pipe
- Relate closed pipe resonance to how wind instruments like clarinets work

In groups, learners are guided to:

- Dip a glass tube into water and hold a vibrating tuning fork over the open end
- Adjust the tube length until resonance is achieved
- Discuss the relationship between length and wavelength: L = λ/4

How does the length of a closed air column affect the sound produced?

- Spotlight Physics Grade 10 pg. 167
- Glass tube
- Glass jar with water
- Tuning fork

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Harmonics in closed pipes
Properties of Waves - Stationary waves in open pipes

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

- Explain harmonics in closed pipes
- Calculate frequencies of overtones in closed pipes
- Connect closed pipe harmonics to the limited overtones in some wind instruments

- Explain stationary wave formation in open pipes
- Calculate fundamental frequency and overtones in open pipes
- Relate open pipe resonance to how flutes and organ pipes produce sound

In groups, learners are guided to:

- Discuss the first harmonic (fundamental frequency) in closed pipes
- Calculate second and third harmonics using f = (2n-1)f₀
- Compare harmonic patterns in closed pipes with open pipes

- Discuss how antinodes form at both ends of an open pipe
- Calculate wavelength and frequency relationships: L = λ/2
- Compare fundamental frequencies in open and closed pipes

Why do closed pipes only produce odd harmonics?
How do stationary waves form in open pipes?

- Spotlight Physics Grade 10 pg. 168
- Digital resources
- Charts showing harmonics

- Spotlight Physics Grade 10 pg. 169
- Digital resources
- Charts showing open pipe harmonics

- Written tests - Problem-solving exercises - Oral questions
- Written tests - Oral questions - Problem-solving exercises

Waves and Optics

Properties of Waves - Meaning of Doppler effect

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

- Explain the meaning of Doppler effect
- Describe how sound frequency changes with relative motion
- Connect Doppler effect to the changing pitch of an ambulance siren

In groups, learners are guided to:

- Discuss the scenario of a blind man detecting vehicle movement by sound
- Explain why the pitch of a siren increases when approaching and decreases when receding
- Research the discovery of Doppler effect by Christian Doppler

Why does the pitch of a siren change as an ambulance passes by?

- Spotlight Physics Grade 10 pg. 173
- Digital resources
- Audio recordings of approaching vehicles

- Oral questions - Observation - Written assignments

Waves and Optics

Properties of Waves - Demonstrating Doppler effect

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

- Demonstrate Doppler effect using sound sources and ropes
- Observe changes in wavelength when source moves towards or away from observer
- Relate the demonstration to how radar speed guns measure vehicle speed

In groups, learners are guided to:

- Move an audio frequency generator towards and away from a stationary observer
- Use a rope to show compression and stretching of waves
- Discuss how wavelength decreases when source approaches and increases when receding

How does the movement of a sound source affect the waves detected by an observer?

- Spotlight Physics Grade 10 pg. 174
- Audio frequency generator
- Rope or spiral spring

- Practical assessment - Observation - Oral questions

Waves and Optics

Properties of Waves - Applications of Doppler effect

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

- Describe applications of Doppler effect in various fields
- Explain how Doppler effect is used in astronomy, medicine, and traffic control
- Connect Doppler applications to ultrasound scans and weather forecasting

In groups, learners are guided to:

- Research applications in astronomy for measuring galaxy movements
- Discuss medical imaging applications like Doppler sonography
- Explore traffic radar and speed camera applications

How is Doppler effect used in medicine and traffic control?

- Spotlight Physics Grade 10 pg. 175
- Digital resources
- Charts showing Doppler applications

- Research presentations - Written tests - Oral questions

Waves and Optics

Radioactivity - Meaning of radioactivity and related terms
Radioactivity - Stability of isotopes and atomic structure
Radioactivity - Types of radiations (alpha, beta, gamma)

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

- Explain the meaning of radioactivity and related terms
- Define nuclear stability, half-life, nuclide, and radioisotope
- Relate radioactivity to smoke detectors and medical treatments

- Explain atomic structure in relation to radioactivity
- Describe how neutron-proton ratio affects nuclear stability
- Connect isotope stability to carbon dating of archaeological artifacts

In groups, learners are guided to:

- Use digital resources to search for meanings of radioactivity terms
- Discuss the meaning of radioactive decay, background radiation, and nucleotide
- Share findings with classmates for peer review

- Discuss the composition of atoms: protons, neutrons, and electrons
- Explain why a 1:1 neutron-proton ratio leads to stability
- Illustrate unstable nuclides using diagrams

What is radioactivity and why do some atoms decay?
How does the neutron-proton ratio affect nuclear stability?

- Spotlight Physics Grade 10 pg. 178
- Digital resources
- Physics reference books
- Spotlight Physics Grade 10 pg. 180
- Digital resources
- Charts showing atomic structure
- Spotlight Physics Grade 10 pg. 181
- Charts showing radiation types

- Oral questions - Written assignments - Group discussions
- Written tests - Oral questions - Diagram labelling

Waves and Optics

Radioactivity - Properties of alpha and beta particles

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

- Describe properties of alpha and beta particles
- Compare penetrating power, ionizing ability, and speed of alpha and beta particles
- Connect alpha radiation properties to smoke detector operation

In groups, learners are guided to:

- Discuss penetrating power: alpha stopped by paper, beta by aluminium
- Compare ionizing power: alpha highest, beta moderate
- Explain deflection in electric and magnetic fields

Why are alpha particles more ionizing but less penetrating than beta particles?

- Spotlight Physics Grade 10 pg. 182
- Digital resources
- Charts comparing radiation properties

- Written tests - Oral questions - Comparison tables

Waves and Optics

Radioactivity - Properties of gamma rays and comparison of radiations

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

- Describe properties of gamma rays
- Compare all three types of radiations using charts and diagrams
- Relate gamma ray properties to their use in X-ray imaging and cancer treatment

In groups, learners are guided to:

- Discuss gamma ray properties: no charge, no mass, highest penetration
- Make charts comparing penetrating power, ionizing effect, and field deflection
- Use diagrams to illustrate effect of magnetic and electric fields on radiations

Why are gamma rays not deflected by electric or magnetic fields?

- Spotlight Physics Grade 10 pg. 183
- Digital resources
- Charts and diagrams

- Chart making - Written tests - Oral questions

Waves and Optics

Radioactivity - Alpha decay and nuclear equations

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

- Write nuclear equations for alpha decay
- Balance nuclear equations showing conservation of mass and charge
- Connect alpha decay to how smoke detectors use americium-241

In groups, learners are guided to:

- Discuss how alpha emission reduces nucleon number by 4 and proton number by 2
- Write nuclear equation for radium-226 decaying to radon-222
- Practice balancing nuclear equations

How do we write nuclear equations for alpha decay?

- Spotlight Physics Grade 10 pg. 186
- Digital resources
- Periodic table

- Written tests - Problem-solving exercises - Oral questions

Waves and Optics

Radioactivity - Beta decay and gamma decay equations
Radioactivity - Uranium-238 decay series

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

- Write nuclear equations for beta and gamma decay
- Explain how beta decay changes a neutron to a proton
- Relate beta decay to carbon-14 dating of organic materials

- Trace the uranium-238 natural decay series
- Write nuclear equations for chain decay reactions
- Connect decay series to geological dating of rocks

In groups, learners are guided to:

- Discuss beta decay: neutron changes to proton and electron
- Write nuclear equation for carbon-14 decaying to nitrogen-14
- Explain gamma decay as energy release without change in mass or atomic number

- Study the uranium-238 decay chain from U-238 to stable Pb-206
- Identify types of radiations emitted at each stage
- Write nuclear equations for each step in the decay series

How do beta and gamma decay differ from alpha decay?
How does uranium-238 eventually become stable lead-206?

- Spotlight Physics Grade 10 pg. 187
- Digital resources
- Periodic table

- Spotlight Physics Grade 10 pg. 188
- Charts showing decay series
- Digital resources

- Written tests - Problem-solving exercises - Oral questions
- Chart interpretation - Written tests - Oral questions

Waves and Optics

Radioactivity - Detection using electroscope and GM tube

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

- Describe detection of radioactive emissions using electroscope
- Explain the structure and operation of a Geiger-Müller tube
- Relate GM tube operation to radiation monitoring in nuclear power plants

In groups, learners are guided to:

- Demonstrate how a charged electroscope loses charge near a radioactive source
- Discuss the components and operation of a GM tube
- Explain how ionization produces pulses counted by a scaler

How does a Geiger-Müller tube detect radiation?

- Spotlight Physics Grade 10 pg. 189
- Electroscope
- Diagrams of GM tube

- Practical demonstration - Oral questions - Written tests

Waves and Optics

Radioactivity - Cloud chambers and nuclear emulsion plates

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

- Describe detection using expansion and diffusion cloud chambers
- Explain the use of nuclear emulsion plates
- Relate cloud chamber tracks to identifying different radiation types

In groups, learners are guided to:

- Discuss the operation of expansion and diffusion cloud chambers
- Observe track patterns for alpha, beta, and gamma radiations
- Explain how nuclear emulsion plates record particle tracks

How do cloud chambers make radiation tracks visible?

- Spotlight Physics Grade 10 pg. 190
- Diagrams of cloud chambers
- Digital resources

- Diagram interpretation - Written tests - Oral questions

Waves and Optics

Radioactivity - Meaning and demonstration of half-life

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

- Explain the meaning of half-life
- Demonstrate half-life concept using water draining from a burette
- Relate half-life to how long radioactive waste remains dangerous

In groups, learners are guided to:

- Define half-life as time for half the radioactive atoms to decay
- Perform water drainage experiment to simulate radioactive decay
- Plot a graph of volume against time and determine half-life

How long does it take for half of a radioactive sample to decay?

- Spotlight Physics Grade 10 pg. 193
- Burette
- Retort stand
- Stop clock

- Practical assessment - Graph plotting - Oral questions

Waves and Optics

Radioactivity - Calculating half-life using graphs and formula
Radioactivity - Significance and applications of half-life
Radioactivity - Nuclear fission and chain reactions

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

- Calculate half-life from decay curves
- Apply the half-life formula N = N₀(½)^(T/t)
- Connect half-life calculations to determining age of archaeological samples

- Explain the meaning of nuclear fission
- Describe chain reactions in nuclear fission
- Relate nuclear fission to electricity generation in nuclear power plants

In groups, learners are guided to:

- Plot decay curves from given data and determine half-life
- Derive and apply the formula N = N₀(½)^(T/t)
- Solve numerical problems involving half-life calculations

- Discuss how uranium-235 splits when bombarded with neutrons
- Explain how chain reactions release enormous energy
- Differentiate controlled reactions in reactors from uncontrolled reactions in bombs

How do we calculate the half-life of a radioactive substance?
How do nuclear power plants generate electricity from fission?

- Spotlight Physics Grade 10 pg. 195
- Graph paper
- Scientific calculators
- Spotlight Physics Grade 10 pg. 197
- Digital resources
- Physics reference books

- Spotlight Physics Grade 10 pg. 198
- Diagrams of chain reactions
- Digital resources

- Written tests - Problem-solving exercises - Graph interpretation
- Written tests - Diagram interpretation - Oral questions

Waves and Optics

Radioactivity - Nuclear fusion and applications

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

- Explain the meaning of nuclear fusion
- Compare nuclear fusion with fission
- Relate fusion to how the sun and stars produce energy

In groups, learners are guided to:

- Discuss how light nuclei combine to form heavier nuclei
- Explain why fusion requires extremely high temperatures
- Compare energy released in fusion versus fission reactions

Why does nuclear fusion power the sun and stars?

- Spotlight Physics Grade 10 pg. 199
- Diagrams showing fusion
- Digital resources

- Written tests - Comparison tables - Oral questions

Waves and Optics

Radioactivity - Applications in medicine and industry

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

- Describe applications of radioactivity in medicine and industry
- Explain how gamma rays treat cancer and sterilize equipment
- Relate industrial applications to detecting pipe leaks and measuring thickness

In groups, learners are guided to:

- Discuss medical applications: cancer treatment, sterilization, imaging
- Explain industrial uses: detecting pipe bursts, thickness measurement, flaw detection
- Research use of radioactive tracers in various fields

How is radioactivity used to treat cancer and detect pipe leaks?

- Spotlight Physics Grade 10 pg. 200
- Diagrams showing applications
- Digital resources

- Research presentations - Written tests - Oral questions

Waves and Optics

Radioactivity - Applications in agriculture and archaeology
Radioactivity - Hazards of radiation and safety precautions

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

- Describe applications of radioactivity in agriculture and archaeology
- Explain carbon dating principles
- Relate radioactive tracers to studying plant fertilizer absorption

In groups, learners are guided to:

- Discuss carbon dating for determining age of fossils and artifacts
- Explain use of radioactive tracers in agriculture
- Calculate ages using carbon-14 decay principles

How do scientists use carbon dating to determine the age of fossils?

- Spotlight Physics Grade 10 pg. 200
- Digital resources
- Charts on carbon dating
- Spotlight Physics Grade 10 pg. 201
- Safety signs
- Digital resources

- Written tests - Problem-solving - Oral questions