Presentation on theme: "Revision 3 Velocity-Time Graphs V t 1/.Constant Acceleration V t 2/.Constant Velocity V t 3/.Deceleration."— Presentation transcript:
Velocity-Time Graphs V t 1/.Constant Acceleration V t 2/.Constant Velocity V t 3/.Deceleration
Velocity-time graphs Velocity m/s T/s 1)Upwards line = Constant Acceleration 2) Horizontal line = Constant Velocity 3) Shallow line = Less Acceleration 4) Downward line = Deceleration
Force causes a body to change velocity The unit is called the Newton (N) A few types of Forces Magnetic Force Tensile Forces Friction happens when 2 bodies are in contact.
Friction Friction is the force that opposes motion of a body when it is in contact with another. Friction happens when 2 bodies are in contact. Lubrication reduces friction
There are THREE types of blood vessels ARTERIES Carry blood away from the heart Thick, muscular, stretchy wall Narrow central tube
VEINS Carry blood towards the heart Thin walls with little muscle Wide central tube Have valves stop the blood flowing backwards
CAPILLARIES carry blood between arteries and veins wall only one cell thick very narrow central tube
Thick muscular walls Divided into 4 chambers Right side pumps blood to lungs Left side pumps oxygenated blood from the lungs to ALL parts of body
The Blood The blood has three main purposes Transport stuff around the body (Food, Oxygen, Carbon Dioxide and Urea) Defence (White Blood Cells) Clotting (Platelets)
Parts of the Blood Plasma – This is the name for the liquid that all the cells float in. Mostly water with Glucose, Protein and Urea dissolved in it.
Parts of the Blood Red Blood Cells – Carry the oxygen around the body. The oxygen combines with HAEMOGLOBIN to turn the blood red. When there is no oxygen in the Haemoglobin it turns purple.
Parts of the Blood White Blood Cells – Eat the bacteria that invade the body. Forming the main part of the IMMUNE SYSTEM. Some can also produce anti-bodies.
Parts of the Blood Platelets – Allow the blood to clot by all rushing to the injury.
Excretion Excretion is the removal of toxic chemical substances Toxic substances are poisonous and can harm the cells of the body if not removed
Excretion SkinSkin - Sweat KidneysKidneys-Urine LungsLungs-Carbon Dioxide + Water
bladder urethra bladder renal artery renal vein ureter urethra kidney Urea is filtered out of the blood mixed with water and excreted as Urine
Atoms C 12 6 Mass Number Mass Number - Number of protons + Neutrons. Atomic Number Atomic Number - Number of protons In a neutral atom the number of electrons and protons are the same. In Carbon it is……… 6
Helium Neutron In this atom we see two neutrons and two protons forming the nucleus. The Neutron has no charge but is the same mass as the proton. Electron Proton
Atomic Particles ParticleChargeMass Where Found Proton+11 amuNucleus Neutron01 amuNucleus Electron 1 amu 1846 Orbiting the nucleus
Sodium 11 Protons 13 neutrons 24 Na 11 Group 1 – one electron in last shell Electric configuration 2,8,1
Isotopes Same number of protons different number of neutrons
Group VII or 0 All in the same group have the same properties Group 8/Noble Gases Non-reactive/Glow with electricity Non-reactive as they have a full outer shell
Ionic Bonding An electron is transferred Na F
Covalent Bonding The electrons are shared Elements in the middle of the periodic table
Monomers small molecules that can be joined together. Polymer is a large molecule made of a chain of smaller molecules
Properties of an Acid Tastes sour Turns blue litmus paper red Has a pH of less than 7 Lemon juice and vinegar are good examples. ACID
Properties of a Base Turns litmus paper blue Has a pH greater than 7 taste bitter and have a slippery feel Bases that are soluble (dissolve in water) are called alkalis Most hand soaps and drain cleaners are bases
p H A measure of how acidic something is
Indicators These are chemicals that change colour in the presence of an acid or a base. We get them from Plants.
All Acid rain is either caused by impurities or not burning fuel well.
Series Circuit -Parallel Circuit
Advantages of parallel circuits… There are two main reasons why parallel circuits are used more commonly than series circuits: 1)Extra appliances (like bulbs) can be added without affecting the output of the others 2) When one breaks they dont all fail
Georg Simon Ohm Resistance Resistance is anything that will RESIST a current. It is measured in Ohms, a unit named after me. The resistance of a component can be calculated using Ohms Law: Resistance = Voltage (in V) (in )Current (in A) V RI
Wiring a plug Earth wire Neutral wire Insulation Live wire Fuse Cable grip
Diode as Valve Only allows current in one direction Forward BiasReverse Bias
Light Dependent Resistor LDR Resistance decreases when light shines on it Used to turn on street light
Nerve cells carry information between the CNS and every area of the body… …nerve cells are very long narrow cells… …there are two types of nerves cells: 1.SENSORY nerves bring messages from the sense organs to the CNS 2.MOTOR nerves bring messages from the CNS to the muscles of the body
The male reproductive system The male reproduction system produces and delivers the male gamete (sperm) link to interactive diagram at KidsHealth Seminal Vesicle Sperm Duct Side view
Occurs when a male gamete (sperm) fuses with the female gamete (egg) to form a zygote Also referred to as conception Sperm + egg = zygote Fertilisation
Fertilisation usually happens in the fallopian tube A fertilised egg – zygote - then moves down into the wall of the uterus / womb Fertilisation
DNA stands for deoxyribonucleic acid It is twisted into a double helix and contains all the codes to build a body the code contains instructions for every structure and function the body will ever need
Weight vs. Mass Mass is the amount of matter in us Same on Earth and Space Weight is the pull of gravity on us Different on Earth and Space 900kg 9000N 0N
Hookes Law Force Extension More force means more Extension Force is proportional to extension
Work Done Lifting Lift a mass of 80kg a height of 6m.. How much work is done? Work done = Force x distance moved Work done = 800N x 6m Work done = 4800 Joules
Pressure – in Fluids Pressure increases with depth
Atmospheric Pressure The earth is covered with layer of Gas. We are at the bottom of a gas ocean 200km deep. The effect of this huge column of gas is 1 Tonne of weight on our shoulders. This is called ATMOSPHERIC PRESSURE Heavy!
Center of Gravity The place where all the mass of the body appears to act. How do we find the center of gravity of this flat piece of card?
Center of Gravity of a Lamina We must freely suspend the lamina from three places Then we trace the plumb line onto the paper. Center of Gravity Where all the mass of the body acts
Moments =Force x Perpendicular distance FORCE =10N Perpendicular distance=5m = 10N x 5m = 50Nm
What is a micro-organism? An organism which is very small. Examples of micro-organisms: Bacteria – e.g. E.coli, Samonella Virus - e.g. flu virus, HIV Fungi
Micro-organisms need: Food Correct temperature Suitable medium on which to grow… Bacteria grow quickly between 30 0 C and 40 0 C
ANTIBIOTICS… these are chemical made by some micro- organisms to kill bacteria. Penicillin was discovered in 1928 by Sir Alexander Fleming White blood cells do the same job. Penicillin is produced by the fungus we call blue mould
BACTERIALVIRAL food poisoningcold septic throatflu bronchitisAIDS meningitis can be caused by either
Fungi Not all are small No chlorophyll so live on organic matter. Yeast and producing antibiotics the main uses Also athletes foot and other poisons
Adding acids to metals Words – gold, corroded, fizzes, disappears If an acid is added to a (fairly reactive) metal the metal will be quickly ________ by the acid. We can see a reaction happening because the mixture _________ and the metal eventually __________. Some metals, like ____, are so unreactive that nothing will happen.
The Reaction Metals + Acid Hydrogen Gas + Salt Magnesium + Hydrochloric Hydrogen + Magnesium Acid Gas Chloride Mg + 2HCl H 2 + MgCl 2
Testing for hydrogen POP
Oxygen Catalyst speeds up reaction but is not used up – Manganese Dioxide Oxygen does not dissolve in the water
Test for Oxygen Relights a glowing splint
Adding acid to carbonates Carbonates are compounds containing carbon and oxygen. When an acid is added to a carbonate the carbonate starts to _______. A gas called ______ _______ is produced. Carbonates used to be used as building materials but arent any more because acid rain would eventually ________ the building. Words – dissolve, fizz, carbon dioxide
Different Metals in Acid Some metals react more than others this is called the reactivity series Calcium MagnesiumZincCopper