physics 1

• What is a ‘system’ in physics?


  An object or group of objects
• What can happen to energy?

  It can be stored or transferred
• What happens when a ‘system’ changes?

  Energy is transferred into or away from the system, between different objects in the system, or between different types of energy stores
• What is a ‘closed system’?

  A system where neither matter nor energy can enter or leave
• What is the net change in the total energy of a closed system?

  Zero
• What is the unit and unit symbol for all types of energy?

  Joules, J
• What is an example of energy stored as elastic potential energy?

  A stretched or compressed spring
• What is an example of energy stored as thermal energy?

  A property an object has because of the kinetic energy of its particles
• What is another name for a thermal energy store?

  Internal energy store
• What is an example of energy stored as kinetic energy?


  Anything that is moving
• What is an example of energy stored as gravitational potential energy?

  Any object above the ground
• What is an example of energy stored as chemical energy?

  An object that has energy stored due to its chemical composition, such as batteries, fuels, or food
• What is an example of energy stored as electrostatic energy?

  Between two charged objects
• What is an example of energy stored as nuclear energy?

  Radioactive nuclei
• What are the four main ways energy can be transferred between energy stores?

  • Heating
  • Radiation
  • Electrical working
  • Mechanical working
• Give an example of how energy is transferred mechanically?

  By a force doing some work
• How is energy transferred by radiating?

  Waves are given out in all directions
• Give an example of how energy is transferred through radiation?

  Light & sound, or anything that is part of the EM spectrum
• Give an example of how energy is transferred electrically?

  A complete circuit allowing charge to flow
• What are the energy store changes when a ball is thrown upwards?

  Kinetic energy store decreases and gravitational potential store increases
• What is another way of saying ‘energy transferred’?


  Work done
• What are the energy store changes when a moving object hits an obstacle?

  The moving object has a store of kinetic energy, which is transferred to other stores when it hits the obstacle and suddenly stops
• What are the energy store changes when an object is accelerated by a constant force?


  Work is done on the object, transferring energy to a store of kinetic energy
• What are the energy store changes when a vehicle applies its brakes to slow down?


  Work is done when the brakes are applied, transferring energy to thermal energy stores
• What are the energy store changes when water is boiled in an electric kettle?

  The kettle transfers a store of electrical energy to thermal energy, which is transferred to the water
• What two measurements do you need to calculate the kinetic energy store of a moving object?

  Mass (in kilograms, kg) and velocity (in meters per second, m/s)
• What is the word equation for calculating kinetic energy?


  Kinetic Energy = ½ x mass x velocity²
• What is the symbol equation for kinetic energy?


  $E_k =$$\frac{1}{2} mv^2$
• What is the word equation for calculating gravitational potential energy?


  Gravitational potential energy = mass x gravitational field strength x height
• What is the symbol equation for calculating gravitational potential energy?


  $E_p =$$mgh$
• What energy transfer happens when an object is falling?

  Stored gravitational potential energy is transferred to its kinetic energy store
• What two ways can elastic potential energy be transferred to an object?

  Stretching or squashing
• What two measurements do you need to calculate the elastic potential energy store of a squashed or stretched object?

  Spring constant (in Newtons per metre, N/m) and extension or compression (in metres, m)
• What does the increase in temperature of a system depend on?

  The mass of the substance, the type of material, and the energy input
• What is the word equation that relates the change in energy of a system, mass, specific heat capacity, and temperature change?

  Change in thermal energy = mass x specific heat capacity x temperature change
• What is the symbol equation that relates the change in thermal energy of a system to the factors that it depends upon?


  $\Delta E =$$mc \Delta \theta$
• What are the units and unit symbols of specific heat capacity?

  Joules per kilogram per degree Celsius, J/kg °C
• What is the specific heat capacity of a substance?

  The amount of energy required to raise the temperature of 1 kg of the substance by 1 °C
• What is power?


  Rate of energy transfer or rate of doing work
• What is the unit and unit symbol of power?

  Watts, W