Grade 09: Science

In this unit, 'Physics: motion', you learn to describe motion with graphs and equations. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Physics: motion' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: describe motion with graphs and equations. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Separate distance from displacement. A child walks 3 m east then 4 m north. The distance travelled is 3 + 4 = 7 m, but the displacement is the straight line from start to finish, 5 m, because 3, 4 and 5 form a right triangle. Speed uses distance, velocity uses displacement with direction.
2. Step 2, Read a distance-time graph. Plot (0 s, 0 m), (2 s, 10 m) and (4 s, 20 m). The points lie on a straight line, so the motion is uniform. The slope is 20 m divided by 4 s, which is 5 m/s, the speed. A flat line means at rest, and a line curving upward means speeding up.
3. Step 3, Read a velocity-time graph. A car starts from rest and reaches 20 m/s in 10 s along a straight sloping line. The slope gives acceleration: 20 / 10 = 2 m/s squared. The area under the line gives distance: a triangle of half times 10 times 20 equals 100 m.
4. Step 4, Use the three equations of uniform acceleration: v = u + at, s = ut + (1/2)at^2 and v^2 = u^2 + 2as. For u = 0, a = 2 m/s^2 and t = 10 s, v = 20 m/s and s = 100 m. Check: v^2 = 400 and 2as = 2 x 2 x 100 = 400, so the equations agree with the graph.
5. Step 5, Describe slowing down. A bicycle at u = 12 m/s brakes with a = -3 m/s^2. It stops when 0 = 12 - 3t, so t = 4 s. Distance s = 12 x 4 - (1/2) x 3 x 16 = 48 - 24 = 24 m. For a class practical, roll a toy car down a ramp on a clear floor, time it and keep feet away from its path.
6. Step 6, Your turn: a ball is dropped from rest and falls for 2 s. Take g = 10 m/s^2. Find its speed and distance fallen using the equations. Answer: v = 0 + 10 x 2 = 20 m/s, and s = (1/2) x 10 x 2^2 = 20 m.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Describe motion with graphs and equations: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Physics: force and laws of motion', you learn to apply Newton's laws and momentum. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Physics: force and laws of motion' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: apply Newton's laws and momentum. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Apply the first law, inertia. A body stays at rest or in steady straight motion unless an unbalanced force acts. Place a card on a plastic cup with a coin on top and flick the card sideways. The coin drops into the cup because it keeps its rest state. Keep your face back and use a light plastic cup.
2. Step 2, Apply the second law, F = ma. A 5 kg trolley pushed by a net force of 20 N gets a = 20 / 5 = 4 m/s^2. Double the force to 40 N and the acceleration doubles to 8 m/s^2. Double the mass to 10 kg with 20 N and it halves to 2 m/s^2.
3. Step 3, Calculate momentum, p = mv. A 1,000 kg car at 20 m/s has p = 20,000 kg m/s. Force equals change in momentum divided by time. Stopping in 5 s needs 20,000 / 5 = 4,000 N, but stopping in 0.5 s needs 40,000 N, which is why airbags and seat belts lengthen the stopping time.
4. Step 4, Apply the third law. When you push a wall, the wall pushes back with an equal force in the opposite direction. The two forces act on different bodies, so they do not cancel. A blown-up balloon released from your hand shoots forward as air rushes backward. Swimmers push water back and move forward.
5. Step 5, Use conservation of momentum. A 2 kg trolley moving at 3 m/s hits a 1 kg trolley at rest and they stick. Total momentum before is 2 x 3 = 6 kg m/s, so after the crash 6 = 3 x v and v = 2 m/s. A 4 kg gun firing a 0.05 kg bullet at 100 m/s recoils at 0.05 x 100 / 4 = 1.25 m/s.
6. Step 6, Your turn: a 3 kg cart moving at 4 m/s hits a 1 kg cart at rest and the two stick together. Find their speed. Answer: momentum before = 3 x 4 = 12 kg m/s; after = 4 kg x v, so v = 12 / 4 = 3 m/s.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Apply Newton's laws and momentum: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Physics: gravitation, work and energy', you learn to use universal gravitation and work and energy. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Physics: gravitation, work and energy' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: use universal gravitation and work and energy. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Use Newton's law of gravitation F = G m1 m2 / r^2 with G = 6.67 x 10^-11 N m^2 kg^-2. For two 10 kg balls 0.5 m apart, F = 6.67e-11 x 10 x 10 / 0.25 = 2.67 x 10^-8 N, tiny.
2. Step 2, Find g on Earth. Using M = 6.0 x 10^24 kg and R = 6.4 x 10^6 m: g = GM/R^2 = 6.67e-11 x 6.0e24 / 4.1e13 = 9.77 m/s2, close to 9.8. Weight = m g, so a 50 kg student weighs 490 N.
3. Step 3, Compute work. A 20 kg box is lifted 3 m. Force needed equals weight 20 x 9.8 = 196 N. Work W = F x d = 196 x 3 = 588 J.
4. Step 4, Use energy. Potential energy at height is mgh = 588 J. If the box falls, KE at the ground is 588 J. Then v = sqrt(2KE/m) = sqrt(2 x 588 / 20) = sqrt(58.8) = 7.7 m/s, the same as sqrt(2gh).
5. Step 5, Power: lifting that 588 J in 4 s gives P = 588 / 4 = 147 W. Conclusion: work transfers energy; energy changes form but its total is conserved.
6. Step 6, Your turn: a 2 kg stone falls from rest through 5 m. Find KE gained and speed (g = 10). Answer: KE = 2 x 10 x 5 = 100 J; v = sqrt(2 x 100 / 2) = 10 m/s.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Use universal gravitation and work and energy: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Physics: sound', you learn to explain sound waves and echo. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Physics: sound' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: explain sound waves and echo. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Describe a sound wave. A tuning fork vibrates and compresses air then leaves a rarefaction, forming longitudinal waves. Mark compressions as high pressure and rarefactions as low pressure on a diagram.
2. Step 2, Define terms. Frequency f in hertz is vibrations per second, wavelength lambda is the distance between two compressions, and wave speed v = f x lambda. For f = 340 Hz and lambda = 1 m, v = 340 m/s.
3. Step 3, Solve for wavelength. Audible range is 20 Hz to 20,000 Hz. At 340 m/s, a 20 Hz sound has lambda = 340 / 20 = 17 m and a 20,000 Hz sound has lambda = 340 / 20000 = 0.017 m.
4. Step 4, Do an echo calculation. A girl claps and hears the echo after 0.6 s. Sound speed 340 m/s means the total path is 340 x 0.6 = 204 m, so the wall is 204 / 2 = 102 m away.
5. Step 5, Link to uses: sonar sends ultrasound (above 20 kHz) and measures echo time, and ultrasound scans use frequencies of a few MHz. Loudness relates to amplitude, pitch to frequency.
6. Step 6, Your turn: a ship's sonar receives an echo after 4 s in water where sound speed is 1500 m/s. Find the depth. Answer: 1500 x 4 / 2 = 3000 m.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Explain sound waves and echo: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Chemistry: matter in our surroundings and is matter around us pure', you learn to classify matter and calculate concentration. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Chemistry: matter in our surroundings and is matter around us pure' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: classify matter and calculate concentration. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Classify matter. Pure substances are elements like iron and compounds like water. Mixtures are homogeneous like salt solution or heterogeneous like soil and water. Test: a pure substance has a fixed melting point.
2. Step 2, Compare mixture and compound. Iron and sulphur mixed can be separated by a magnet. Heated together they form iron sulphide, a compound with different properties, not attracted by the magnet.
3. Step 3, Calculate mass percent. A solution contains 10 g of salt in 90 g of water. Solution mass = 100 g. Mass by mass percentage = 10 / 100 x 100 = 10 per cent.
4. Step 4, Calculate volume percent. 25 mL of alcohol in 100 mL of solution gives 25 per cent by volume. Mass by volume of 5 g in 200 mL is 5 / 200 x 100 = 2.5 per cent.
5. Step 5, Describe particles. States differ by spacing and motion. Evaporation occurs below boiling, and rate rises with temperature, surface area and wind. Convert 300 K to Celsius: 300 - 273 = 27 C.
6. Step 6, Your turn: find the concentration of a solution of 20 g sugar in 180 g water. Answer: 20 / 200 x 100 = 10 per cent by mass.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Classify matter and calculate concentration: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Chemistry: atoms, molecules and the structure of the atom', you learn to use symbols, formulae and the atomic model. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Chemistry: atoms, molecules and the structure of the atom' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: use symbols, formulae and the atomic model. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Write symbols and valencies. Sodium Na is +1, chlorine Cl is -1, oxygen O is -2, calcium Ca is +2. Criss-cross: Na (1) and Cl (1) give NaCl. Ca (2) and Cl (1) give CaCl2. Al (3) and O (2) give Al2O3.
2. Step 2, Calculate molecular mass. Using atomic masses H = 1, C = 12, O = 16, Ca = 40: H2O = 2 + 16 = 18 u. CO2 = 12 + 32 = 44 u. CaCO3 = 40 + 12 + 48 = 100 u.
3. Step 3, State the laws. Conservation of mass: in a reaction, 4 g of hydrogen forms water with 32 g of oxygen to give 36 g of water, so mass is unchanged. Constant proportion: in water H to O mass is always 1 to 8.
4. Step 4, Describe the atom. Sodium has 11 protons, 12 neutrons and 11 electrons, so atomic number 11 and mass number 23. Electron configuration is 2, 8, 1, with one valence electron that is easily lost.
5. Step 5, Compare isotopes: chlorine-35 and chlorine-37 have the same 17 protons but 18 and 20 neutrons. Average atomic mass about 35.5 u because of the abundance, roughly 3 to 1.
6. Step 6, Your turn: write the formula for magnesium chloride and its molecular mass (Mg 24, Cl 35.5). Answer: MgCl2; 24 + 71 = 95 u.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Use symbols, formulae and the atomic model: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Biology: the fundamental unit of life and tissues', you learn to describe cell organelles and plant and animal tissues. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Biology: the fundamental unit of life and tissues' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: describe cell organelles and plant and animal tissues. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Describe the cell as the basic unit of life. All living things are made of cells, and new cells come from existing cells. An amoeba is one cell, a human has trillions. To see onion peel cells, stain a thin peel with dilute iodine, add a cover slip gently and use a lamp, never direct sunlight. Wash hands afterwards.
2. Step 2, Describe the parts every cell has. The plasma membrane controls what enters and leaves. The cytoplasm is the jelly where reactions happen. The nucleus holds the DNA and directs the cell. Plant cells also have a cellulose cell wall, a large vacuole and chloroplasts, while animal cells have no wall and only small vacuoles.
3. Step 3, Match organelles to jobs. Mitochondria release energy from glucose, so they are called powerhouses. Ribosomes make proteins. Rough ER, which carries ribosomes, moves proteins, and smooth ER makes fats. The Golgi apparatus packs and sends out substances. Lysosomes digest waste, and chloroplasts carry out photosynthesis.
4. Step 4, Describe plant tissues. Meristematic tissue at root and shoot tips divides to make the plant grow longer. Permanent tissues are parenchyma (stores food), collenchyma (flexible support), sclerenchyma (hard, dead support), xylem (carries water and minerals up) and phloem (carries made food in both directions).
5. Step 5, Describe animal tissues. Epithelial tissue covers skin and lines the gut. Connective tissue includes blood, bone, cartilage and fat. Muscle tissue has three kinds: striated in limbs, smooth in the gut and cardiac in the heart. Nervous tissue is made of neurons. Under a microscope, a 10x eyepiece with a 40x objective magnifies 400 times.
6. Step 6, Your turn: name the organelle that releases energy and the plant tissue that carries water up from roots. Answer: the mitochondrion releases energy from glucose, and xylem carries water and minerals upward.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Describe cell organelles and plant and animal tissues: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

In this unit, 'Biology: diversity, health and natural resources', you learn to classify organisms and explain disease and resource cycles. You work with notes, a worked line and a self-mark. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Biology: diversity, health and natural resources' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: classify organisms and explain disease and resource cycles. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Classify with the five kingdoms: Monera (bacteria), Protista (amoeba), Fungi (mushroom), Plantae (mango tree) and Animalia (tiger). Take the tiger: Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Felidae, Genus Panthera, species tigris.
2. Step 2, Trace disease. Malaria is caused by Plasmodium protozoa spread by the female Anopheles mosquito. It is infectious. Diabetes is a non-infectious disease. Prevention for malaria: nets, drain standing water, prompt treatment.
3. Step 3, Explain vaccination. A weakened antigen trains the immune system to make antibodies and memory cells. A later exposure to the real pathogen is then met by a fast response. Herd immunity protects those not vaccinated.
4. Step 4, Follow the nitrogen cycle: atmospheric N2, nitrogen fixation by Rhizobium in legume root nodules, nitrates in soil, uptake by plants, passage to animals, decomposition to ammonia, and denitrification to N2.
5. Step 5, Follow the carbon cycle: plants take CO2 by photosynthesis, animals release it by respiration, and burning fossil fuels adds CO2. The greenhouse effect traps heat; rising CO2 warms the climate.
6. Step 6, Your turn: name the kingdom and one disease prevention for a mushroom and for cholera. Answer: Fungi; cholera is prevented by clean boiled water and sanitation.

Activity. About 30 to 40 minutes of class work, then one short practice task for home. Keep evidence: a worked task and a corrected copy.

Standard to meet. Classify organisms and explain disease and resource cycles: at least 8 of 10 marks on a short task, with one line of reasoning for each answer.

On the slide: L1 Basic · Using my five senses

Notes: Name the five senses and use them to describe a safe object. Notes: place a leaf, a smooth stone and a soft cloth in a bag; learners touch and describe each. Never taste or smell unknown things; teach children to ask first. Grades 1 and 2.

On the slide: L2 Awareness · Fair tests

Notes: Describe a fair test by naming what is changed, what is measured and what stays the same. Notes: plant two seed pots, one in light and one in the dark, with equal water and soil. Learners say the one changed factor, and draw both pots after a week. Grades 3 and 4.

On the slide: L3 Foundation · Measuring and recording

Notes: Measure length, mass, time and temperature and record them in a table. Notes: a plant grows 2 cm in 4 days, which is 0.5 cm a day. Learners take three readings of 12, 14 and 13 mm, find the mean of 13, and say why repeats help. Grades 5 and 6.

On the slide: L4 Practitioner · Variables, graphs and density

Notes: Apply a formula and draw a graph from a fair test. Notes: density equals mass over volume; a metal block of 54 g and 20 cm3 has density 2.7 g/cm3. Learners plot mass against volume for three blocks and read the gradient. Dry the benchtop before using water. Grades 7 and 8.

This course: Grade 09 Science is at this level. Its units include Physics: motion; Physics: force and laws of motion; Physics: gravitation, work and energy; Physics: sound and more.

On the slide: L5 Specialist · Evidence, anomalies and models

Notes: Analyse data, spot an anomaly and judge how well a model fits the evidence. Notes: readings of 5.1, 5.3, 5.2 and 7.9 hold one anomaly at 7.9, so the mean of the rest is 5.2. Learners suggest a cause, repeat the trial and write a conclusion that cites the numbers. Grades 9 and 10.

On the slide: L6 Advanced · Modelling and curve fitting

Notes: Apply least-squares fitting and error reasoning to link data to a model. Notes: the points (1,2.1), (2,3.9), (3,6.2), (4,7.8), (5,10.1) give slope 1.99 and intercept 0.05, with R squared 0.997. Learners explain what the intercept means and whether a straight line is right.

On the slide: L7 Super expert · Study design and sample size

Notes: Evaluate and create a study with a clear hypothesis, controls, sample size and ethics approval. Notes: to detect a 5-unit difference with spread 10 at 5 per cent significance and 80 per cent power needs about 63 per group. Learners write a pre-registered plan and list the risks and consent steps.