P1 physics

• Particle model


  Includes the development of the atom, solids, liquids, and gases, and density
• Changes of state


  Includes specific heat capacity, specific latent heat, and the difference between heat and energy
• Pressure


  Includes atmospheric pressure, gas pressure, and fluid pressure (for triple students)
• Density


  Mass divided by volume, units are kg/m^3
• Calculating volume


  1. For a rectangle: width x length x height

  2. For a cylinder: π x radius^2 x height
• Specific heat capacity


  The amount of energy required to heat up 1 kg of a substance by 1 degree C, units are J/kg/°C
• Specific heat capacity


  Determines how much energy a material can store
• Specific heat capacity


  Relates to heating and cooling
• Latent heat


  The energy required for a substance to change state, units are J/kg
• Specific latent heat of fusion


  Energy required to melt or freeze a substance
• Specific latent heat of vaporization


  Energy required to boil or condense a substance
• Sublimation is the process of going directly from a solid to a gas
• Determining specific heat capacity experimentally


  Measure mass, change in temperature, and energy transferred (using power, current, voltage, and time)
• Pressure


  Force divided by area, units are N/m^2 or Pa
• Weight


  Mass times acceleration due to gravity, units are N
• Boyle's law


  Pressure is inversely proportional to volume
• Pressure x volume = constant (for triple students)
• Atmospheric pressure


  • Decreases with increasing altitude as there is less air above pushing down
• Boyle's law


  Relationship between pressure and volume of a gas at constant temperature
• Using Boyle's law


  1. Determine pressure before and after

  2. Use equation p1v1 = p2v2
• Boyle's law is a constant relationship
• Boyle's law equation p1v1 = p2v2 is only for triple science students
• Atmospheric pressure


  Pressure caused by the weight of air above a point on the Earth's surface
• As altitude/height increases


  Atmospheric pressure decreases
• Calculating pressure of a fluid at a depth

  Use equation: pressure = density of fluid x gravitational field strength x depth
• This fluid pressure equation is only for triple science students
• Solids


  • Particles have a regular, organised arrangement and are all touching
  • Solids are generally denser than liquids and gases
  • Solids have fixed shape and fixed volume
• Liquids


  • Particles have a random arrangement but are still touching
  • Liquids have a fixed volume but no fixed shape
• Gases


  • Particles have a random arrangement and are far apart
  • Gases have no fixed volume or shape
• Solids have lower average kinetic energy of particles than the strength of intermolecular bonds
• Temperature


  Measure of average kinetic energy of particles
• Heat


  Measure of energy, has an absolute scale with a true zero
• The current model of the atom is called the quantum model
• Historical development of atomic models


  1. Democritus - atoms as indivisible spheres

  2. Dalton - different types of atoms can combine

  3. Thomson - plum pudding model with electrons and positive charge

  4. Rutherford - positive nucleus with electrons orbiting
• Rutherford's atomic model


  • Positive nucleus containing most of the mass
  • Electrons orbiting the nucleus
  • Most of the atom is empty space
• Bohr developed the idea of electron shells around the nucleus
• Electrons are negative, neutrons are neutral, protons are positive
• Sublimation


  The process of going directly from a solid to a gas, without passing through the liquid phase.
• Condensation


  The process of a gas turning directly into a liquid, typically when the temperature or pressure of a gas is decreased, or when the gas comes into contact with a surface that is cooler than the gas.
• Deposition


  The process of a gas turning directly into a solid, without passing through the liquid phase.