# Physics SS 2 Curriculum Guides – Gas Laws, Heat Energy (Temperature and Its Measurement and Heat Enemy Measurement), Linear Momentum and Mechanical Energy

THEME – CONSERVATION PRINCIPLES

### INSTRUCTIONAL MATERIALS

1. U-tube, coloured water, meter rule

2. Bowl of water, test tube

3. Boyle’s law apparatus or J-tube, mecury, metre rule

4. Large beaker, J-tube with coloured water, source of heat, thermometer, ruler or meter rule, water.

### LEARNING OBJECTIVES

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

1. explain, using the ideas of the kinetic theory of gases.

• the variation of volume with temperature of a gas when the pressure is kept constant.
• the variation of pressure with volume of a gas when temperature is kept constant.

2. explain Charles’ and Boyle’s laws of gases.

3. deduce the general gas law from a given mass of gas which obeys Charles’ law.

4. solve simple problems involving the gas laws.

5. identify and use instruments for measuring pressure.

### FOCUS LESSONS

1. Measurement of gas pressure

2. Barometer in practical use.

3. Boyle’s law and its application.

4. Charles’ law and its application.

5. General gas law

### LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. demonstrate the relationship between the volume of a given mass of gas and its absolute temperature.

2. use Boyle’s law apparatus to show relationship between the pressure of a given mass of air and its volume.

STUDENT’S ACTIVITIES

The students,

1. use U-tube manometer to measure pressure.

2. construct a simple barometer.

### LESSON EVALUATION

Students to,

1. explain gas laws using kinetic theory of gases.

2. solve simple problems on:

• Charles’ law
• Boyle’s law
• General gas law

THEME – CONSERVATION PRINCIPLES

### INSTRUCTIONAL MATERIALS

1. Thermometers, cold an hot water

2. Different types of liquid-in-glass thermometers e.g. clinical, min and max thermometers

3. Container with movable position e.g. bicycle pump or round or flat bottomed flask with delivery tube connected to a water manometer, thermometer

4. Glass, capillary tube, biro tube, coloured liquid, hot water, cold water, beaker, bunsen burner

5. Constant/platinum wire, simple electric circuit with ammeter and voltmeter or multimeter

6. Water, beaker, bunsen burner or stove thermometer

7. Connecting wires of two different materials e.g. copper, iron, loe, cold water, hot water, galvanometer

8. Dressings/charts

### LEARNING OBJECTIVES

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

1. construct a device for measuring the temperature of a body.

2. use the variation of:

• pressure of a gas with temperature.
• the expansion of solid, liquid or gas with temperature.
• electrical resistance of a material to measure the temperature of a body.

3. distinguish between heat and temperature and between temperature points and temperature intervals.

4. select those liquids which are suitable for use in liquid-in-glass thermometers from a given list of liquids and their properties.

5. state the instrument used for measuring temperature.

6. explain the device for measuring the temperature of an environment.

7. describe the absolute scale of temperature and explain the meaning of the absolute zero of temperature.

8. convert a given temperature on the Celsius scale to a temperature on the Kelvin scale.

9. describe the kinetic molecular model of temperature.

### FOCUS LESSONS

1. Temperature and its measurements

2. Thermometers

• constant volume gas thermometer
• liquid-in glass thermometer
• resistance thermometer
• thermocouple

3. Absolute scale of temperature

4. Pressure and temperature of a gas

5. Pressure law

6. Molecular explanation of temperature

### LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. demonstrates how to calibrate a thermometer in Celsius scale.

2. demonstrates how to construct a resistance thermometer and a thermocouple.

3. deduces the absolute zero of temperature from a graph of pressure against temperature.

4. derives the relationship between the pressure of a gas and the kinetic energy of its particles.

STUDENT’S ACTIVITIES

The students,

1. calibrate a thermometer in Celsius scale

2. construct a resistance thermometer and a thermocouple and use them to measure the temperature of water and immediate environment.

### LESSON EVALUATION

Students to,

1. determine properties of thermometeric substances

2. apply the relationship between:

• the pressure of a gas with temperature
• volume with temperature
• resistance of a material with temperature to determine unknown temperature or resistance

3. students to explain the concept of absolute zero of temperature leading to Kelvin scale

4. student to use kinetic molecular theory to explain change in temperature

THEME – CONSERVATION PRINCIPLES

### INSTRUCTIONAL MATERIALS

1. Bunsen burner or stove, measuring cylinder thermometer, calorimeter or empty milk tin.

2. Different liquids-water, engine oil, glycerine

3. Calorimeter or empty tin, solid of known specific heat capacity,water thermometer, weighing balance.

4. Test tube, naphthalene, water bath (beaker of water) stop watch or clock, source of heat.

5. Beaker of warm water, thermometer, pieces of ice block, blotting paper, weighing scale.

6. Beaker of cold water, thermometer, steam from boiling water (dry), weighing scale, source of heat.

7. Water, salt, iron fillings,metal container, source of heat, thermometer

8. Round bottom flask, running water, source of heat, cork to cover flask, clamp to cold flask.

9. Ether or methylated spirit.

### LEARNING OBJECTIVES

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

1. explain the relationship between the heat supplied to a substance and:

• its temperature change at constant mass.
• its mass at constant temperature change.

2. explain the terms, specific heat capacity and thermal capacity

3. explain why there is unequal rise in temperature for different substances of the same mass supplied with the same quantity of heat

4. calculate unknown quantities using the relation H = MC, ΔT when no change of state is involved

5. determine the melting point of a solid and boiling point of a given liquid

6. list the effects of impurities and pressure on the melting point of solid and boiling point of liquid

7. solve simple problems involving latent heat

8. distinguish between evaporation and boiling and explain sublimation

9. explain the working principles of such common devices as:

• refrigerator
• air conditioner
• pressure cooker

10. explain the effects of humidity on personal comfort

### FOCUS LESSONS

• concept of specific heat capacity
• its measurements
• its significance

2. Latent heat

• concept of latent heat
• measurements of specific latent heat of fusion and of vaporisation
• effect of pressure and impurities on melting and boiling points

3. Some applications of latent heat

4. Evaporation, boiling and sublimation

5. Relative humidity and dew point

### LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. Derive the relationship between energy supplied to a substance and the temperature change for the substance, keeping mass constant (H & ΔT, M constant)

2. Derive the relationship between the energy supplied to a substance and its mass keeping the temperature change constant (H & ΔT, M constant).

STUDENT’S ACTIVITIES

The students,

1. determine the specific heat capacity of water by method of mixture

2. determine the specific heat capacity of a sold

3. estimate the rate of supply of heat by a bunsen burner to a mug of water

4. heat naphthalene and plot its heating and cooling curves

5. determine the specific latent heat of fusion of ice

6. determine the specific latent heat of vaporization of steam

7. investigate the effects of impurities and pressure on melting and on boiling points.

8. use ether to show that rapid evaporation causes cooking

### LESSON EVALUATION

Students to,

1. explain the meaning of specific heat capacity – state the relationship between the quantity of heat, mass and change in temperature.

2. to calculate the specific heat capacity of solids and liquids.

3. explain

• melting point
• boiling point
• latent heat
• evaporation
• sublimation

4. explain the effects of impurities and pressure on melting and boiling points.

5. solve simple problems on calculation of latent heat.

6. explain the working principle of a refrigerator, air conditioner and pressure cooker.

7. answer questions on the effects of humidity.

THEME – CONSERVATION PRINCIPLES

### INSTRUCTIONAL MATERIALS

1. Ticker-timer

2. Trolleys

3. Billard balloons, small oranges

4. Balloons

5. Charts showing rocket propulsion

### LEARNING OBJECTIVES

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

1. state and explain in his/her own words, the meaning of laws of motion.

2. show graphically:

(a) the relationship between the acceleration produced by a given set of forces acting on the same mass.

(b) the relationship between the acceleration produced by a constant force on varying masses.

(c) know that the results from (a) and (b) lead to the equation F = ma

3. solve simple problems based on Newton’s laws of motion and the principle of momentum.

4. state and explain the meaning of law and conservation of linear momentum.

5. solve simple problems involving the conservation of linear momentum.

6. explain:

• why walking is possible.
• why gun receils when fired.
• how a rocket is propelled.
• how a jet plane is propelled.

7. explain inertial mass and the relationship between mass and weight

8. explain why the weight of a body may vary from place to place.

### FOCUS LESSONS

1. Momentum and impulse

2. Newton’s laws of motion

3. Conservation of linear momentum

4. Collisions

5. Inertia, inertial mass and weight

6. Application of Newton’s laws of motion.

### LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher demonstration using a timing device e.g. (A ticker-timer) to determine:

1. acceleration of a falling body.

2. relationship between acceleration and mass when the acceleration force is constant.

STUDENT’S ACTIVITIES

The students,

1. use collision of two bodies in a straight line to investigate conservation of linear momentum.

2. investigate elastic and inelastic collisions of trolleys.

3. show the principle in rocket propulsion using a balloon.

### LESSON EVALUATION

Students to,

1. explain the concept of momentum and impulse.

2. state and explain the meanings of each of Newton’s three laws of motion.

3. establish the relation between force and acceleration leading to the equation F = ma.

4. solve simple problems on Newton’s laws of motion

5. students to explain the concept of conservation of linear momentum.

6. students to solve simple problems on inertia and elastic collision.

THEME – CONSERVATION PRINCIPLES

### INSTRUCTIONAL MATERIALS

1. Lever, pulley hydraulic press, wheel and axle

2. Inclined plane, the screw, wedge

3. Crowbar, claw hammer, pliers

4. Fire-arm longs

5. Butcracker, wheelbarrow

6. Chart of all above

7. Inclined plane, rectangular piece of wood

8. Spring balance, rectangular piece of wood, table or bench surface.

### LEARNING OBJECTIVES

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

1. calculate the kinetic and potential energy of a body.

2. verify conservation of energy principles and show that the total energy is conserved for a given set of data on the energy of a particle in a conservation field.

3. determine a machine and list at least five simple machines.

4. define and calculate:

• a. force ratio
• b. velocity ratio
• c. efficiency for a simple machine and write the mathematical relationship between (a), (b) and (c).

5. state how friction can be reduced in the moving parts of a given machine

6. perform a simple experiment using a spring balance to determine the co-efficient of friction between two surfaces.

### FOCUS LESSONS

1. Concept of work as a measure of energy

2. Quantitative treatment of mechanical energy

3. Conservation of mechanical energy

4. Application of mechanical energy

5. Machines:

• types of machine
• velocity ratio
• efficiency

6. Friction

### LESSON PRESENTATION

TEACHER’S ACTIVITIES

The teacher,

1. use a body falling under gravity to demonstrate conservation of mechanical energy.

2. use a lever to demonstrate the working of a simple machine.

3. lead discussion on static and dynamic friction.

STUDENT’S ACTIVITIES

The students,

1. classify machines into lever and inclined plane.

2. classify levers on the basis of the relative position of the fulcrum, effort and load.

3. use an inclined plane as a simple machine and from it determine its efficiency, the velocity ratio and force ratio.

4. identify the simple machines that make up a given complex machine such as a bicycle.

5. determine the co-efficient of static friction between two surfaces.

### LESSON EVALUATION

Students to,

1. solve simple problems on mechanical energy.

2. solve simple problems that relate to work done with energy.

3. to classify machines and levers.

4. solve problems to determine force ratio, velocity ratio and efficiency of simple machines.

5. differentiate simple machine from complex machines.

6. Students to solve simple problems on friction.