Physics paper 1

• A scalar quantity is just a number
• Vector quantity


  A number and a direction
• Distance


  Measured in meters
• Speed/Velocity


  Measured in meters per second
• Time


  Measured in seconds
• Distance-time graphs


  • Increasing slope = moving faster
  • Flat line = not moving
• Calculating speed from distance-time graphs

  Gradient = distance/time
• Velocity-time graphs


  • Flat line = moving at steady speed
  • Increasing = accelerating
• Calculating acceleration from velocity-time graphs


  Gradient = velocity/time
• Calculating distance from velocity-time graphs

  Area under the graph
• Calculating acceleration from velocities

  Acceleration = (final velocity - initial velocity)/time taken
• Velocity units


  Meters per second
• Acceleration units


  Meters per second squared
• Gravity on Earth


  10 Newtons per kilogram
• Acceleration due to gravity on Earth

  10 meters per second squared
• Calculating resultant force

  Difference between forces
• Force


  Measured in Newtons
• Mass


  Measured in kilograms
• Weight


  Measured in Newtons, depends on gravity
• Centripetal force


  Force causing circular motion
• Momentum


  Mass x velocity, measured in kg.m/s
• Law of conservation of momentum
• Calculating force from momentum


  Force = (final momentum - initial momentum)/time
• Stopping distance


  • Thinking distance + Braking distance
  • Increases with speed
• Factors affecting thinking distance

  Alcohol, drugs, tiredness
• Factors affecting braking distance

  Tire condition, road condition, vehicle weight
• Kinetic energy

  0.5 x mass x velocity^2, measured in joules
• Work done

  Force x distance, measured in joules
• Types of energy

  • Gravitational potential
  • Electrical
  • Elastic potential
  • Kinetic
  • Sound
  • Light
  • Nuclear
  • Chemical
  • Thermal
• Calculating change in gravitational potential energy

  Mass x gravity x change in height, measured in joules
• Wasted energy


  Energy that is not the intended useful output, often dissipates into surroundings
• Sankey diagram

  Visual representation of energy efficiency
• Infrared cameras can detect heat loss from buildings
• Ways to improve energy efficiency of buildings

  Insulation, double glazing, draft excluders
• Efficiency

  Useful power out / total power in, can be expressed as percentage or decimal
• Renewable energy sources

  • Sun
  • Wind
  • Water (tidal, hydroelectric, wave)
  • Geothermal
• Non-renewable energy sources

  • Fossil fuels (coal, oil, gas)
  • Nuclear
• Advantages of renewable energy

  • Don't release CO2
  • Inexhaustible
  • Non-polluting
• Disadvantages of renewable energy

  • Intermittent (solar, wind)
  • Disruptive to environment (tidal, hydroelectric)
  • Limited locations (geothermal)
• Advantages of fossil fuels/nuclear

  • Readily available
  • Cheap