KEY WORDS: Velocity Acceleration Deceleration Speed

1. P2 REVISION – CHAPTER 1 – Motion Distance-time Graphs Using Graphs The gradient of the line on a distance-time graph represents _________. The ______________ the gradient, the greater the speed. If an object is stationary, the line on a distance-time graph is ______________. If an object is moving at a constant speed, the line on a distance-time graph is a straight line that slopes _____________. Velocity-time graphs Velocity & Acceleration Calculate the gradient of the line on a distance-time graph to give you the speed of an object. The gradient of the line on a velocity-time graph represents ______________. The steeper the ____________, the greater the acceleration. What does a horizontal line show on a velocity-time graph? What area on a velocity-time graph shows the distance? Calculate the gradient of the line on a velocity-time graph to give you the acceleration of an object. KEY WORDS: Velocity Acceleration Deceleration Speed ASSESSMENT: If the value calculated for acceleration is negative, the body is decelerating – slowing down. A deceleration is the same as a negative acceleration.

2. P2 REVISION – CHAPTER 2 – Forces Forces between objects. Resultant Force On the Road The resultant force is a single force that has the same effect as all the forces acting on an object. If an object is accelerating there must be a resultant force acting on it. If an object is accelerating what 3 things can it be doing? If a vehicle is travelling at a steady speed, the resultant force on it is __________. The driving forces are equal and opposite to the frictional forces. Forces are measured in newtons, N. What is the rule with regard to forces? Force and Acceleration What always causes an acceleration? The bigger the resultant force on an object, the greater its ___________________. F = m x a F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s² Reaction time depends on the ____________. Braking distance depends on the ___________, ___________ _____________ and the condition of the vehicle. KEY WORDS: Force Newton Mass ASSESSMENT: Acceleration is a change in velocity. An object can accelerate by changing its ________________ even if it is going at a ______________ ____________. Therefore a ___________________ ______________ is needed to make an object change __________________.

3. P2 REVISION – CHAPTER 2 – Forces continued. Falling Objects Stretching & Squashing Force and Speed Issues What does elastic mean? The extension of a spring is DIRECTLY PROPORTIONAL to the force applied to it, provided the limit of proportionality is not exceeded. How do we know that it is directly proportional? Extension is the difference between the length of the spring and its ____________ _________. Hooke’s Law Equation: F = k x e Where F is the force applied in newtons, N k is the spring constant of the spring in newtons per metre, N/m e is the extension in metres, m What is the spring constant of a spring? The force of gravity is called ___________ An object acted on only by gravity will accelerate at about ___________. F = m x a Where: F is the resultant force in newtons, N. m is the mass in kilograms, kg a is the acceleration in m/s² Becomes: W = m x g Where: W is the weight in newtons, N m is the mass in kilograms, kg g is the acceleration due to gravity in m/s² If an object falls through a fluid the fluid exerts a __________ force on the object. Faster the object falls, the bigger the drag force becomes until it becomes equal to the weight of the object. Resultant force will then be ___________. This is called ________________ _______________. DON’T FORGET: Mass is the amount of matter in an object. Weight is the force of gravity acting on it. Reduces the speed of a vehicle reduces the amount of what? What is this called? Reducing air resistance, making a vehicle more _________________ also improves fuel economy. Speed cameras are used to discourage motorists from doing what? In pairs they can be used to calculate __________________ speed. What happens if you are caught speeding? When does skidding happen? What happens when you skid? _________ ___________ surfaces are used to reduce or prevent skidding. How do these surface work? Where are they used? KEY WORDS: Gravitational Drag force Terminal velocity Weight Elastic Proportionality ASSESSMENT:

4. P2 REVISION – CHAPTER 3 – Work, Energy & Momentum Energy & Work Explosions Work is done on an object when a force makes the object move. Energy transferred = work _______ What is the unit for both work and energy? W = F x d Where: W is the work done in joules, J F is the force in newtons, N d is the distance moved in the direction of the force in metres, m Work done to overcome _____________ is transferred as energy that heats the objects that rub together and the surroundings. Momentum has both size and direction. One direction must be ________________, therefore momentum in the opposite direction is negative. In an explosion the objects will move apart with _______________ and ______________________ momentum. One being positive the other ______________. So the total momentum after the explosion is ____________. Gravitational Potential Energy Kinetic Energy The object will move apart with different speeds if they have _____________ _______________. KEY WORDS: Work Friction Kinetic energy Elastic potential energy ASSESSMENT:

5. P2 REVISION – CHAPTER 3 –Work, Energy & Momentum cont. Impact Forces Car Safety When vehicles collide the force of the impact depends on what 3 things? When two vehicles collide they exert ______________ and __________________ forces on each other, also their total _______________________ is unchanged. What is impact time? Cars today have several different safety features built into them, to reduce the forces on the occupants of the car in a collision. How do side impact bars, seat belts, air bags and crumple zones help with safety? Questions What can we use to find out the speed of a car before an impact? What is the unit of momentum? Where do you have crumple zones on a car and why? KEY WORDS: Impact time Crumple zone ASSESSMENT:

6. P2 REVISION – CHAPTER 4 – Current Electricity Electrical Charges Electric Circuits Electric symbols If you rub two electrically insulating materials are rubbed together, __________________ are rubbed off one material and deposited on the other. Objects that have opposite electric charges ______________ each other, if they have the same electric charge they___________. I is the current in amperes, A Q is the charge in coulombs, C t is the time in seconds, s. Every component has an agreed circuit symbol. Make sure you can recognise and draw them! Resistance Current is measured with an ammeter. Where are ammeters placed in relation to the component? What is the unit of current? The potential difference(pd) across a component is measured with a voltmeter. These are always placed in parallel with the component. What is the unit of potential difference? V is ? W is ? Q is ? Don’t forget units! R is ? V is ? I is ? Don’t forget units! KEY WORDS: Insulating Electron Attract Repel Resistance Series ASSESSMENT: Ohm’s law: states that the current through a resistor at constant temperature is directly proportional to the potential difference across the resistor.

7. P2 REVISION – CHAPTER 4 – Current Electricity Cont. Current-Potential Difference Graphs Series Circuits A current-potential difference graph for a resistor. How are the components connected in a series circuit? What happens if there is a break in the circuit? Is the current the same or different through each component? If you add together the potential difference what does it give you? The resistance of the individual components add up to give the total resistance of the circuit. A current-potential difference graph for a filament bulb, line is a curve so the current is not directly proportional to the __________________ ___________________. The current in a diode flows in one direction only, in the reverse direction the diode has a very high resistance so the current will be what? Parallel Circuits How are the components connected in a series circuit? What happens if there is a break in the circuit? Is the pd across each component the same or different? The bigger the resistance of a component, the ______________ the current through it. Use this equation to work out the current through a component in a parallel circuit. Thermistor: Resistance _______________ if its temperature increases. LDR: resistance decreases if the light intensity on it ___________. KEY WORDS: Diode Filament bulb Resistor Thermistor ASSESSMENT:

8. P2 REVISION – CHAPTER 5 – Mains Electricity Alternating Current Electrical Energy & Charge Fuses Direct current is supplied by cells and batteries and passes round the circuit in one direction. Alternating current is from the mains, how does it travel? Frequency of am ac supply can be worked out from an oscilliscope trace using the equation: How does a fuse work? Where is a fuse fitted in a circuit? How does a circuit breaker work? An electric current is the flow of what? What is the equation that relates to charge, current and time? When charge flows through a resistor, what makes it hot? What can you use this equation for? Cables & Plugs Electrical Power & Potential Difference Electrical Issues Electrical faults are dangerous what two things can they cause? Why must you check cables, plugs and sockets for damage regularly? What must you not touch with wet hands? Why are filament bulbs very inefficient? Power can be calculated using the above equation. Why are the pins of a plug made of brass? What does the earth wire earth? Why are some cables thicker than others? Using the current and the pd and the equation above enables us to calculate the power of an appliance. To work out the correct rating in amperes for a fuse rearrange the above equation, what would the equation now be? KEY WORDS: Current Frequency Oscilloscope Circuit breaker ASSESSMENT:

9. P2 REVISION – CHAPTER 6 – Radioactivity Observing Nuclear Radiation Nuclear Reactions An atom has a small central _________________, which contains the ____________ and _________________, this is then surrounded by_______________________. The nuclei of radioactive substances are unstable, to become stable they go through a process called radioactive decay. The 3 types of radiation emitted are: Where does background radiation come from? Remember: Radioactive decay is random we cannot predict or influence when it happens! Discovery of the Nucleus What is an atom called if it loses or gains electrons? What is an isotope? When a nucleus emits an alpha particle the atomic number goes down by _____ and the mass number goes down by ___. When a nucleus emits a beta particle the atomic number goes up by ___ and the mass number stays the same. Is there any change when a nuclear emits gamma radiation? Scientists originally called the model of the atom the ‘plum pudding’. Rutherford, Geiger and Marsden then did an alpha particle scattering experiment, they fired alpha particles at thin gold foil. Most passed straight through the foil, what does this mean? KEY WORDS: Ion Isotope Nucleus Proton Electron Radiation ASSESSMENT: Some of the alpha particles are deflected through small angles, what does this mean? A few rebound through large angles what does this mean?

10. P1 REVISION – CHAPTER 6 – Radioactivity cont. Half-Life Alpha, beta & gamma radiation What is the half-life of a radioactive isotope? The number of atoms of a radioactive isotope and the activity both decrease by __________ every half life. Remember what stops each type of radiation. Radioactivity at Work Ionisation is when nuclear radiation travels through a material, colliding with the atoms within it. This then knocks electrons off, creating ions. KEY WORDS: Ionisation Half-life Tracer Radioactive dating ASSESSMENT: Radioactive Dating: What is this used for? What do we need to do it?

11. P1 REVISION – CHAPTER 7 – Energy From the Nucleus Nuclear Fission The Early Universe Nuclear fission is the splitting of a nucleus into two approximately equal fragments and the release of two or three neutrons. What two fissionable isotopes are most commonly used in nuclear reactors? When does a chain reaction occur? How and when do many scientists think the universe was created? What pulled the gas and dust together to form stars? What are very large groups of stars called? Nuclear Fusion Nuclear Issues Nuclear fusion is the process of forcing two nuclei close enough together so they form a single larger nucleus. What is released when this happens? Where does nuclear fusion take place? What is a major source of background radiation? Name two other sources of background radiation. How is nuclear waste stored? Why must it be stored securely? KEY WORDS: Star Nuclear fusion Chain reaction Nuclear fission ASSESSMENT:

12. P1 REVISION – CHAPTER 7 – Energy From the Nucleus cont Life History of a Star How the chemical elements formed Protostar: Gas and dust cloud in space that can go on to form a star. Low mass star: Protostar main sequence star red giant white dwarf Black dwarf High mass star: Protostar main sequence star red supergiant Supernova black hole if sufficient mass. What will the sun eventually become? What is a supernova? Gas, rocks and dust The sun forms at the centre of a spinning cloud of dust, gas and rock. The sun’s energy evaporates ice and drives gas away from the inner solar system, leaving rocks behind. The rocky planets form near the Sun and the gas giant planets form further away. The minor planet Pluto orbits the Sun beyond the giant planets. Elements as heavy as iron are formed inside stars as a result of nuclear _______________. Elements heavier than iron are formed in supernovas, along with lighter elements. What were the sun and the rest of the solar system formed from? KEY WORDS: Pro star Supernova Neutron star ASSESSMENT: