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Physics (Electricity :warning: (Current and charge (Diode image (image),…

- - - - Charging by friction
        Some insulators become charged when you rub them with another insulator such as a dry cloth. When you rub the insulator, electrons are transferred from of the materials to the other
- - - - Energy of a moving object
        
        K.e. = 1/2 m v2
    - - Energy of an object due to its position
        
        E.p.=m g h
    - - Elec. energy = Voltage x Current x Time (V I T)
    - - Force= Spring constant x Extension (F=K e)
  - - - Usually thermal or sound
- - - - Rutherford's model- designed by Ernest Rutherford. 1911 Designed after firing alpha particles at gold foil, some particles were deflected and some passed straight through, proved that atoms were not solid balls.
  - - - A beta particle is a high speed electrons that has a charge of -1.
        
        Will travel a few meters in the air
        -moderatly ionizing
        -can be stopped by aluminium 3mm thick
    - - Alpha particles are He 2+, comprises of 2 protons and 2 neutrons, it is highly ionizing, bumps into things a lot, it can travel through around 10 cm of air and is stopped by paper and skin.
    - - Gamma radiation is a form of electromagnetic radiation,not a type of particle. When a atoms nucleus decays and emits gamma radiation, there is no change too the make-up of the nucleus and so a new element is formed
- - - - Non-renewable resources
        
        Fossil Fuels
        
        Coal
        
        Oil
        
        Natural gas
        
        Advantages
        
        It’s environmentally friendly
        
        Safer and easier to store, by far
        
        Natural gas is reliable
        
        It’s less costly compared to other fossil fuel energy sources
        
        Effects of fossil fuels
        
        Release carbon dioxide when they burn
        
        Adds to the green house effect
        
        Increases global warming
        
        Nuclear Fuels
        
        Uranium
    - - Wind turbines harness the power of the wind and use it to generate electricity.
        
        About 40 per cent of all wind energy in Europe blows over the UK, making it an ideal country for domestic turbines
        
        Benefits are
        
        Cut your electricity bills
        
        Get paid for what you generate
        
        Cut your carbon footprint
        
        Store electricity for a calm day
    - - Solar panel electricity systems capture the sun's energy using photo voltaic cells.
      - Benefits
        
        Cut your electricity bills
        
        Get paid for the electricity you generate
        
        Sell electricity back to the grid.
        
        Cut your carbon footprint.
    - - The waves arriving cause the water in the chamber to rise and fall, which means that air is forced in and out of the hole in the top of the chamber.
    - - Fuel is relatively cheap
      - Power stations themselves are very expensive
      - Hard to dismantle old stations
        
        Become a hazard
    - - no fuel costs.
      - No harmful polluting gases are produced.
    - - Most parts of the world do not have suitable areas where geothermal energy can be exploited.
- - - - Convection
        
        Liquids and gases are fluids. The particles in these fluids can move from place to place. Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy.
      - Radiation
        
        All objects give out and take in thermal radiation, which is also called infrared radiation. The hotter an object is, the more infrared radiation it emits.
        
        Infrared
        
        Infrared radiation is a type of electromagnetic radiation that involves waves. No particles are involved, unlike in the processes of conduction and convection, so radiation can even work through the vacuum of space. This is why we can still feel the heat of the Sun, although it is 150 million km away from the Earth.
      - Heat loss
        
        loss
        
        Heat is lost:
        
        through the roof
        
        through windows
        
        through gaps around the door
        
        through the walls
        
        through the floor
        
        Heat is lost:
        
        through the roof
        
        through windows
        
        through gaps around the door
        
        through the walls
        
        through the floor
        
        Heat can be transferred from place to place by conduction, convection and radiation.
      - Conduction
        
        Heat is thermal energy. It can be transferred from one place to another by conduction.
        
        Metals are good conductors of heat, but non-metals and gases are usually poor conductors. Poor conductors are called insulators.
        
        Heat energy is conducted from the hot end of an object to the cold end.
        
        The electrons in a piece of metal can leave their atoms and move about in the metal as free electrons. The parts of the metal atoms left behind are now positively charged metal ions.
        
        The ions are packed closely together and they vibrate continually. The hotter the metal, the more kinetic energy these vibrations have. This kinetic energy is transferred from hot parts of the metal to cooler parts by the free electrons.
        
        These move through the structure of the metal, colliding with ions as they go.