physics

• The different types of energy stores are

  1. Thermal
  2. Kinetic
  3. Gravitational
  4. Elastic potential
  5. Chemical
  6. Magnetic
  7. Electrostatic
  8. Nuclear
• Energy is transferred mechanically, electrically, by heating or by radiation.
• Kinetic energy is the energy an object has because of its motion.
• Formula for Kinetic energy

  KE= 0.5 (kinetic constant) x m x v²
• Potential energy is the energy held by an object because of its position relative to other objects.
• Gravitational potential energy is the energy stored in an object due to its position in a gravitational field.
• Formula for GPE

  = mass(kg) x gravity (N/kg) x height (m)
• Gravity on earth = 9.8 N/Kg
• Potential Difference (voltage) is a measure of the energy given to the charge carriers in a circuit.
• Potential Difference (V)= Current (A) x Resistance (Ω)
• Resistors are components that resist the flow of electrical current, they have a resistance value measured in ohms (Ω).
• Density is a substance's mass per unit of volume.
• Density = mass/volume
• Specific latent heat is the amount of energy required to change the state of 1kg of a material without changing its temperature.
• Latent Heat = Specific Latent Heat x Mass
• The specific latent heat of water is 4200 J/g
• Thermal conductivity is how well a material can transfer thermal energy from one part to another.
• Formula for specific latent heat

  Energy(E) = Mass(M) x Specific Latent Heat
• Non-renewable energy resources will run out one day.
• Non-renewable energy resources are also fossil fuels and nuclear fuels.

  1. Coal
  2. Oil
  3. (Natural) Gas
• Non-renewable energy resources provide most of our energy.
• Renewable energy resources will never run out.

  1. The sun(solar)
  2. Wind
  3. Water waves
  4. Hydro-electricity
  5. Bio-fuel
  6. Tides
  7. Geothermal
• The size of the current is the rate of flow of charge.
• When current flows past a point in a circuit for a length of time then the charge that has passed is given by this formula:

  Q = It
• power is the rate of transfer of energy, measured in watts(w) or kilowatts(Kw).
• The more powerful an appliance is, the faster the rate at which it transfers energy.
• power(p)= energy transferred(J)/times(s)
• power wasted by an appliance

  = total power input - useful power output
• Internal energy is the total energy stored by particles in a system. It is the sum of all the energies contained in the system, such as kinetic energy, potential energy, chemical energy, etc.
• Resistance is the restriction of electrons flowing (stops them).
• Resistance is measured in Ohms(Ω)
• Ohms law is the current directly proportional to the potential difference.
• Components that obey Ohms law are Ohmic conductors.
• Elastic potential energy is the energy stored in a stretched or compressed elastic object.
• Epe= 0.5 x k x e²
• Solids have strong forces of attraction that hold the particles together in a fixed, regular arrangement. Not much energy so they can only vibrate about their positions.
• Liquids have weaker forces of attraction. The particles are close together but can move past each other. They form irregular arrangements. They have more energy than a solid. Move-in random directions at low speed.
• Gases have almost no forces of attraction. They have more energy than liquids and solids. They are free to move. They are constantly moving in random directions at different speeds.
• Efficiency is a measure of how much energy is converted.
• Efficiency = Useful output/ total input