Energy

• Energy cannot be created or destroyed
• Energy is transferred through energy stores
• Energy is tran when something change. This may happen between energy stores in the same object or between energy stores in different objects wiyhin a system
• A system is an object or a group of objects that are interacting
• One energy store inceases the other decreases
• Energy can be transferred by force moing an object, electricity, heating or waves
• Energy transfers can be useful or not useful. This is whenever energy is transferred some of the energy is dissipated. This means thath energy is transferred in a way that is not useful
• Efficiency = useful output energy/ total input energy
• Polyst is a goos insulator because it is a poor thermal conductor, this means that energy transfer by conduction is slowso the drink remains hotter for longer
• When objects move friction opposes the direction of movemen, thiscauses energy to be dissipated by heating
• Kinetic energy(J)= 0.5 x mass(kg) x speed^2

  1kg x 1000= 1000g
• Elastic potential energy = 1/2 x spring constant(n/m)x extension squared(m)
• 100mm/1000= 0.1 m
• 100g=0.1kg= 1N
• Calculate gradient change in y/ change in x
• Gravitational potential= mass x gravitational field strength x height

  cm /100= m
• When an object begins to move towards ground level, the gravitational potential energy store decreases and the kinetic energy store increases
• At ground level the gravitational potential energy store is 0J. Energy is conseved so this means that when an object falls gravitational energy = kinetic energy
• When asibstance is heatef energy is transferred to the substance. this oncreases tge thermal energy of the system. This caused the temperature to increase however thr size of the temperature increas depends on

  • the mass of the substance
  • the specufic heat capacity
• Power is the rate atvwhuch energy is transfered. Energy transfered = work done
• Power = energy transferred/ time
• Foscil fules are dead animals or plant that have been compressws over time
• What is chemical energy?


  Energy stored in chemical bonds of substances
• How is kinetic energy defined?


  Energy possessed by an object due to its motion
• What does gravitational potential energy depend on?


  Object's position in a gravitational field
• What is elastic potential energy?


  Energy stored in an object that is stretched or compressed
• What is thermal energy related to?


  Random motion of particles in an object
• What does magnetic energy refer to?


  Energy stored in magnetic fields around magnets
• What is electrostatic energy?


  Energy stored in electric fields around charged objects
• What is nuclear energy?


  Energy stored in the nucleus of an atom
• What are the key mechanisms of energy transfer?


  Mechanical, radiation, electrical, matter transfer
• What is mechanical transfer?


  Transfer through heating, work, or waves
• How does matter transfer energy?


  By particles moving from one place to another
• What is the principle of energy conservation?


  Energy is always conserved during transfer
• From where to where does energy transfer occur?


  From higher energy to lower energy regions
• What energy transformation occurs in an electrical kettle?

  Electrical energy transforms to thermal energy
• What energy transformation occurs on a roller coaster?

  Gravitational potential energy transforms to kinetic energy
• What energy transformation occurs in a solar panel?


  Electromagnetic energy transforms to electrical energy
• What happens when voltage is applied in an electrical circuit?


  Electrons start moving, creating an electric current
• How does wind carry thermal energy?


  By moving particles from one location to another