technical sciences grade 10 textbook and workbook · technical sciences grade 10 textbook and ......

Technical SciencesGrade 10

Textbook and Workbook

Santie du Plessis • Carlien FanoyJudy McDougall

Example

Doc ScientiaPosbus 7011

Ansfrere 1711

www.docscientia.co.za

For any queries and feedback: [email protected]

Jacques Fanoy or Stephan FanoyOffice: 011 472 8728

Fax: 086 546 1423

ISBN: 978-1-920537- -

First edition January 2015

Graphic design: Helene Jonck

All rights reserved. No part of this publication may be reproduced in any form or by any means –

mechanical or electronic, including recordings or tape recordings and photocopying – without the prior permission of the publisher.

Example

INDEXUnit Page

TERM 1

MECHANICS

Unit 1 MEASUREMENT

1.1 Units and measuring

1.1.1 Fundamental units of CGS system

1.1.2 Fundamental units of SI system

1.1.3 Derived units

Exercise 1

1.1.4 Prefixes to standard units

1.1.5 Conversion of units

1.1.6 Units used in technology

Exercise 2

1.2 Scientific notation

1.2.1 Use scientific notation

1.2.2 Examples of scientific notation in technology

Exercise 3

1.3 Use of formulae

1.3.1 Identify a formula

1.3.2 Replace given values and solve

1.3.3 Examples in technology

Exercise 4

Summary of Unit 1

Mind maps of Unit 1

Unit 2 MOTION

2.1 Rate

2.2 Vectors and scalars

2.2.1 Direction of a vector

2.2.2 Graphical representation of vectors

2.2.3 Properties of vectors

2.2.4 Net or resultant vector

2.2.5 Addition of vectors

Exercise 5

2.3 Motion in one dimension

2.3.1 Position

2.3.2 Distance and displacement

Exercise 6

2.3.4 Velocity

Exercise 7

2.3.5 Acceleration

Experiment 1

Exercise 8

Summary of Unit 2

Mind maps of Unit 2

Unit 3 FORCES

3.1 What is a force

3.1.1 Contact forces

3.1.2 Non-contact forces

Example

3.2 Different forces

3.2.1 Tension

Practical demonstration

3.2.2 Normal force (FN or N)

3.2.3 Force of gravity (Fg or w)

3.2.4 Frictional force (f or Ff )

Experiment 2

3.3 Force diagrams and free body diagrams

Exercise 9

3.4 Resultant

3.5 Equilibrant

Experiment 3

3.6 Equilibrium of forces

Exercise 10

Summary of Unit 3

Mind maps of Unit 3

Term test

TERM 2

MECANICS

Unit 4 SIMPLE MACHINES

4.1 Moment of a force

Exercise 11

4.2 Laws of moments

Experiment 4

Exercise 12

4.3 Types of beams

4.3.1 Balke

4.3.2 Cantilevers

4.3.3 Simply supported beams

4.3.4 Shear force

4.3.5 Benidng moments

4.3.6 Equilibrium

Exercise 13

4.4 Examples

4.4.1 Levers

4.4.2 Fulcrum

4.2.3 Tipes of levers

Projek

4.4.4 Mechanical advantage

Experiment 5

Exercise 14

Summary of Unit 4

Mind maps of Unit 4

Unit 5 ENERGY

5.1 Gravitational potential energy

Experiment 6

5.2 Kinetic energy

Exercise 15

Example

5.3 Mechanical energy

Exercise 16

Summary of Unit 5

Mind maps of Unit 5

TERM 2

MATTER AND MATERIALS

Unit 1 CLASSIFICATION OF MATTER

1.1 Properties

1.2 Pure substances

1.2.1 Elements

1.2.2 Compounds

Exercise 17

1.3 Naming of compounds

1.3.1 Table of ions

1.3.2 Molecular formula

1.3.3 Stock notation

1.3.4 Names of substances

Exercise 18

1.4 Chemical reactions

1.4.1 Balancing

1.4.2 General chemical reactions

Exercise 19

Summary of Unit 1

Mind maps of Unit 1

Term test

TERM 3

MATTER AND MATERIALS

Unit 2 METALS, METALLOIDS AND NON-METALS2.1 Introduction

2.2 Properties

2.2.1 Electrical conductors, metalloids and insulators

Experiment 7

2.2.2 Thermal conductors and insulators

Experiment 8

2.2.3 Magnetic and non-magnetic materials

Experiment 9

Exercise 19

Summary of Unit 2

Mind maps of Unit 2

Unit 3 STRUCTURE OF THE ATOM3.1 Atom

3.2 Isotopes

Exercise 20

3.3 Position on Periodic Table

3.4 Electron configuration

Exercise 21

Summary of Unit 3

Mind maps of Unit 3

Example

TERM 3

ELECTRICITY AND MAGNETISM

Unit 1 ELECTROSTATICS

1.1 Charge

Experiment 10

1.2 Origin of charge

1.2.1 Friction

1.2.2 Contact

1.3 Conservation of charge

Exercise 22

Summary of Unit 1

Mind maps of Unit 1

Unit 2 ELECTRICAL CIRCUITS

2.1 Circuits

2.2 Current strength

2.3 Potential diffference and emf

Experiment 11

Exercise 23

Summary of Unit 2

Mind maps of Unit 2

Term test

TERM 4

ELECTRICITY AND MAGNETISM

Unit 2 ELECTRICAL CIRCUITS

2.4 Resistance

Experiment 12

2.4.1 Resistors in series

Experiment 13

2.4.2 Resistors in parallel

Experiment 14

Exercise 24

Summary of Unit 2

Mind maps of Unit 2

Unit HEAT AND THERMODYNAMICS

1. Heat

2. Temperature

3 Types of thermometers

3.1 Alcohol thermometer

3.2 Mercury thermometer

3.3 Thermoelectric thermometer

3.4 Uses

Experiment 15

4 Temperature scale

4.1 Celsius scale

4.2 Kelvin scale

Experiment 16

Exercise 25

Summary of Unit

Mind maps of Unit

Term test

Example

KWARTAAL 4: HITTE EN TERMODINAMIKA

Doc Scientia TEGNIESE WETENSKAPPE hand- en werkboek - Graad 10 7

HEAT AND THERMODYNAMICS

1. Heat

Heat is sometimes also known as warmth.It is an amount of energy that is transferred from one object to another until both objects have the same temperature. It is a form of energy.We measure heat in joule (J) since it represents an amount of energy that is transferred.

2. Temperature

Temperature is an indication of how hot or cold an object is.

Temperature is measured with a thermometer in degrees Celsius (°C) or in kelvin (K).According to the kinetic molecular theory (particle theory) that you studied in Grade 9, hot particles in the solid state vibrate more than cold particles.Liquid and gas particles move even faster since their temperature is higher than the corresponding temperature of a solid. Temperature is therefore dependent on the movement energy of the particles of the substance.

Heat or warmth is an amount of energy that is transferred from one object to another.

Quick factsThe SI unit of temperature is kelvin (K).

Alcohol thermometer

Thermoelectric thermometer

Mercury thermometer

Uses

Heat

Temperature

Types of thermometers

Temperature scaleCelsius

Kelvin

Heat and temperature

Example

hitte en termodinamika

8 Doc Scientia TEGNIESE WETENSKAPPE hand- en werkboek - Graad 10

Temperature is the measure of the average kinetic energy of the particles of a substance.EK = 1/2mv2

Study the following two objects of which the temperatures initially differ:

Object A is warmer and therefore the particles have a larger kinetic energy than object B. We know from own experience that both objects would have the same temperature after a while as represented in the second diagram.The warm object (A) will become cooler and the cold object (B) will become warmer.

This means that the temperature of the warm object dropped since heat or warmth flowed to the cold object and caused the temperature of the cold object to rise.

Energy en route from the warm object A with a large average EK to the cold object B with a smaller average EK. This energy is called warmth.

Eventually all the molecules have the same average kinetic energy so the temperature of both objects are the same.

3 Types of thermometers

There are many types of thermometers.The most important types are the alcohol thermometer, the mercury thermometer and the thermoelectric thermometer.

3.1 Alcohol thermometer

Alcohol thermometers have coloured alcohol (usually red, to make it more visible) in the inside space.

Alcohol is a good choice because it can measure verylow temperatures up to -115°C since the freezing point of alcohol is so low.

A B

Example



Advantages:• Cheap• Requires little maintenance.• Alcohol expands easily and moderately.• Accurate readings• It can measure very low temperatures up to -115°C.

Disadvantages:• Alcohol in the thermometer is colourless without colourant.• Alcohol evaporates easily which could cause inaccuracy.• Cannot measure high temperatures.• Alcohol tends to cling to glass which means a correct reading cannot be taken immediately with a drop in temperature.• Absorbs some of the system's warmth and affects the accuracy of readings.

3.2 Mercury thermometer

The mercury thermometer has mercury in the inside space. Mercury is visible since it is silver and shiny.

Advantages:• Mercury expands quickly and evenly.• More accurate readings than the alcohol thermometer• Mercury do not cling to the glass during temperature drops.

Disadvantages:• Low temperatures cannot be measured, because the freezing point of mercury is -40°C.• Poisonous• Although the mercury is visible, it is sometimes difficult to see.• Absorbs the warmth of the system and therefore affects the accuracy of readings.

Quick factsA small difference in temperature changes the level of the alcohol quite a lot.

Quick factsAlcohol also has a low boiling which makes it unable to measure very high temperatures.

Example



3.4 Uses

Thermometers are used for a variety of purposes in the everyday life. The following are examples thereof:• Thermostats in fridges and freezers• Thermostats in air-conditioning units• Thermostats in machinery like car engines• To measure the temperatures of the atmosphere• To determine the temperatures of ovens• Aeroplanes must determine whether the defrosting of the wings is required by monitoring the temperature of the wings.• The temperature of roads in countries where it snows a lot will determine whether salt is necessary on the roads or not.• Maximum-minimum thermometers are used to measure the temperatures for different weather conditions.• Clinical thermometers are used to determine whether a patient has a fever or not.

3.3 Thermoelectric thermometer

The thermoelectric thermometer is the most accurate of the three types. It consists of a thermocouple which consists of two different types of metalloids.The one part of the thermocouple is always at a constant cold temperature and the other part is where the warmer value is measured.The difference in temperature of the thermocouple causes an induced emf which is then converted in a temperature scale.The larger the induced emf, the higher the temperature.

Advantages:• Very accurate• Does not absorb the system's warmth.• Does not affect the system's temperature.• Digital scale is easier to read.

Quick factsMercury is extremely poisonous. If the thermometer breaks it must be handled very carefully.

Quick factsThermoelectric thermometer can measure very accurately over a large range of temperatures (0,001 K – 2 000 K).

Example



How to use a thermometerhttps://www.youtube.com/watch?v=hmMZDJ3Rwyo • Never use the thermometer as a stirrer – it can break and is too expensive.• Lift the thermometer off the bottom of the container and keep it away from the side of the container. The sides and bottom of the container (especially not during heating) do not necessarily have the same temperature as the content of the container.

Experiment 15 Date:Use a mercury thermometer and measure the temperature of:• Ice water• Tap water• Boiling water

Aim: To measure the temperatures of different states of water – vapour excluded.

Apparatus:• Thermometer (preferably more than one type: alcohol, mercury, thermoelectric)• Ice (broken)• Tap water• Boiling water• Three measuring cups

Method:1. Mark the three measuring cups as ice water, tap water and boiling water.2. Place broken ice, tap water and boiling water in the applicable beakers.3. Place the thermometer(s) in the beaker with boiling water and determine the temperature. Record the value(s) in the table.4. Place the thermometer(s) in the beaker with tap water and determine the temperature. Record the value(s) in the table.5. Place the thermometer(s) in the beaker with ice water and determine the temperature. Record the value(s) in the table.

Results:

State Alcohol thermometer (°C)Mercury thermometer

(°C)Thermoelectric

thermometer (°C)

Broken ice

Tap water

Boiling water

Interesting factsA pyrometer is a non-contact thermometer which is used, amongst others, to measure very high temperatures, for instance when metals are melted or to measure the temperature of lava in a volcano.

Example



1. Give possible reasons for the readings to differ.

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

2. Which one of the readings is the most accurate?

___________________________________________________________________________

Conclusion:1. What can you deduce about the temperature of the different states of water?

_________________________________________________________________________________

_________________________________________________________________________________

4 Temperature scale

Primarily, there are three scales that are commonly used to measure temperatures.The three scales are Celsius, Kelvin and Fahrenheit.Although Fahrenheit is commonly used in England, the scales used for scientific purposes are the Celsius and the Kelvin scales.

4.1 Celsius scale

The Celsius scale was developed by defining the freezing point of water and the boiling point of water as 0°C and 100°C respectively.These two positions are marked on the thermometer.The distance between the two positions on the relevant thermometer is then divided into 100 pieces which each represent one grade Celsius.The Celsius scale is the scale that is commonly used to measure temperatures for everyday purposes.

4.2 Kelvin scaleThe Kelvin scale is the scale that is commonly used for thermodynamics.This scale is related to the Celsius scale but the zero point of the scale is defined differently.The zero point of the Kelvin scale is known as absolute zero point. This value is equal to -273°C.

Example



RememberRemember that the kelvin scale starts lower than the Celsius scale.

The starting point of the Kelvin scale is therefore 273° lower than that of the Celsius scale.

Conversions between the two scales are done by adding or subtracting the value of 273.

x °C + 273 = X Kand

X K – 273 = x °C

Examples1. 25°C + 273 = 298 K2. -45°C + 273 = 228 K3. 452 K - 273 = 179°C4. 186 K - 273 = -87°C

Quick factsThe absolute zero indicates the position where particlesof a substance have no kinetic energy.

Quick factsT is temperature in K.t is temperature in °C.

Interesting factsDaniel Gabriel Fahrenheit developed this scale by choosing the freezing point of water as 32°F and the boiling point of water as 212°F.Between the two boundaries there are 180 grade. However, this scale is not used for scientific purposes.If you ever want to convert °C to °F, you can use the following equation.

°F = 9/5°C +32

Example



Experiment 16 Date:Measure the melting point of candle wax.

Aim: To measure the melting point of candle wax.

Apparatus:• Candle• Water • Knife• Bunsen burner• Thermometer• 500 mℓ measuring beaker• Tripod stand• Gauze• Large test tube• Retort stand

The following representation gives a visual reference to quickly compare the different relevant temperatures.

boiling point of water

human body temperature

K °C °F

room temperature

melting point of water

absolute zero

Kelvin Celsius Fahreinheit

Example



Method:1. Use a knife to cut the candle wax into small pieces. Ensure that all the wax pieces are more or less the same size.2. Place the thermometer in the test tube.3. Add the pieces of candle wax to the test tube, next to the thermometer so the test tube is approximately halfway filled with wax.4. Place the half-filled test tube in the measuring beaker which stands on top of the tripod stand. 5. Use the clamp to clamp the test tube in such a way that the base thereof does not touch the measuring beaker.6. Pour tap water into the measuring beaker until the water level is above the level of the candle wax.7. Heat the water in the measuring beaker until the candle wax melts.8. Take the temperature of the candle wax every 30s and record the readings

Results:

Time (s) Temperature (°C) Time (s) Temperature (°C)

0 180

30 210

60 240

90 270

120 300

150

1. What is the temperature at which candle wax melts?

___________________________________________________________________________Example



2. Draw a graph of the heating of candle wax.

3. Why do we use a water bath to heat the candle wax?

_________________________________________________________________________

_________________________________________________________________________

_________________________________________________________________________

Conclusion:1. What is the melting point of the candle wax?

_________________________________________________________________________

Example



Exercise 25 Date:1. Give the definition of heat or warmth.

_____________________________________________________________________________

2. Give the definition of temperature.

_____________________________________________________________________________

_____________________________________________________________________________

3 What is the unit in which the following is measured:3.1 Heat or warmth

_____________________________________________________________________________

3.2 Temperature

_____________________________________________________________________________

4. Name the three types of thermometers commonly used.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

5. Complete the following table to indicate the benefits and disadvantages of each type of thermometer.

Type of thermometer

Benefits Disadvantages

Alcohol

Mercury

Thermoelectric

Example



6. Name three different uses of thermometers in the technology.

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

7. Which temperature scale is used for thermodynamic purposes?

_____________________________________________________________________________

8. Complete the following table by converting the temperature from Celsius to Kelvin or vice versa.

Temperature in °C Temperature in K

56

0

-136

158

254

367

0

221Example



Summary• Heat or warmth is a quantity of energy transferred from one object to another.• Heat/warmth is measured in joule (J).• The SI unit of temperature is kelvin (K).• Temperature is the measure of the average kinetic energy of the particles a substance consists of. EK = 1/2mv2

• Different thermometers:

Alcohol thermometer Mercury thermometerThermoelectric thermometer

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• Cheap• Requires little maintenance.• Expands easily and moderately.• Accurate readings• It can measure very low temperatures up to -115°C.

• Mercury expands quickly and evenly.• More accurate readings than the alcohol thermometer• Mercury do not cling to the glass during temperature drops.

• Very accurate• Does not absorb warmth from the system• Does not affect the system's temperature.• Digital scale is easier to read.

Dis

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• Alcohol is colourless without colourant.• Alcohol evaporates easily which could cause inaccuracy.• Cannot measure high temperatures.• Alcohol tends to cling to glass which means a correct reading cannot be taken immediately with a drop in temperature.• Absorbs some of the system's warmth and affects the accuracy of readings.

• Low temperatures cannot be measured, because the freezing point of mercury is -40°C.• Poisonous• Although the mercury is visible, it is sometimes difficult to see.• Absorbs the warmth of the system and therefore affects the accuracy of readings.

• Uses of thermometers: - Thermostats in fridges, freezers and air-conditioning units - To measure temperature, e.g. atmosphere, earth - Determine whether the defrosting of aeroplane wings is required. - Determine whether salt is necessary on the roads for snow.• Temperature scale - Celsius scale Commonly used to measure temperatures for everyday use, e.g. oven temperature. Measured in celsius (°C). - Kelvin scale Commonly used in thermodynamics. SI unit for temperature - kelvin (K)• x °C + 273 = X K• X K – 273 = x °C

Example

Definition of warmth Definition of temperature. Temperature scales

Types of thermometers

Alcohol thermometerAdvantages

Disadvantages

Thermoelectric thermometerAdvantages

Mercury thermometerAdvantages

Nadele

HEAT OR WARMTH

Example

technical sciences grade 10 textbook and workbook · technical sciences grade 10 textbook and ......

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