Physics 1 - Energy

• A system


  An object or a group of objects
• Kinetic energy


  What is the energy associated with movement?
• Elastic potential energy


  What type of energy is stored in stretched objects
• Nuclear energy


  What type of energy is found in the nuclei of atoms?
• Gravitational Potential Energy


  What type of energy is found in objects raised off the ground?
• Thermal energy


  What type of energy is stored as heat?
• Chemical energy


  What type of energy is found in bonds between substances?
• Kinetic energy = 0.5 x mass x speed^2


  What is the equation to work out the kinetic energy of a moving object?
• Elastic potential energy = 0.5 x spring constant x extension^2


  What is the equation to work out the elastic potential stored in a spring?
• Joules (J)


  What is the unit for energy?
• G.P.E = mass x gravitational field strength x height


  What is the equation to work out gravitational potential energy of an object raised off the ground?
• kg


  What is mass measured in?
• m/s


  What is speed measured in?
• N/m


  What is spring constant (Ek) measured in?
• m


  What is extension measured in?
• 0.2m


  If an object started at 5cm long and stretched to 25cm then what would be the value for extension?
• N/kg


  What is gravitational field strength measured in?
• Change in thermal energy = mass x specific heat capacity x temperature change


  How can you calculate the change in thermal energy?
• The amount of energy required to increase the temperature of 1kg of a substance by 1 degree celsius


  What is specific heat capacity?
• Power


  The rate at which energy is transferred or the rate at which work is done
• Power = Energy transferred / time


  How do you calculate power using energy transferred?
• Power = work done / time


  How do you calculate power using work done?
• Watts (W)


  What is power measured in?
• 1J


  How much energy is transferred each second if the power is 1W?
• The higher the power, the faster the object would be lifted.


  If you have two motors lifting a weight to the same height but one has more power, then what will be the difference between the rate at which they are lifted?
• Energy can be transferred usefully, stored or dissipated, but cannot be created or destroyed


  What is the law of the conservation of energy?
• Wasted energy


  What do we call energy that is dissipated?
• There will be no net change in the total energy


  In a closed system what will happen to the total energy?
• Use lubricants or insulation to reduce energy being wasted as heat


  How can we reduce the amount of waste energy in a system?
• The higher the conductivity, the faster the rate of conduction


  How does thermal conductivity of a material affect the rate of conduction across the material?
• The thicker the wall, and the lower its conductivity, the slower it will lose heat.


  How does the thickness of a wall affect the rate of cooling of a building?
• Efficiency = Useful output energy transfer/total input energy transfer


  How do you calculate efficiency using energy output?
• Efficiency = useful power output/total power input


  How do you calculate efficiency using power?
• Fossil fuels (coal, oil and natural gas) and nuclear fuel


  What are the main non-renewable energy resources on Earth?
• Bio-fuel, wind, hydroelectric, geothermal, tidal, solar and wave


  What are the main renewable energy resources on Earth?
• Transport, electricity generation and heating


  What are the main uses of energy resources?
• Wind


  Which energy resource depends on the wind, and is very changeable?
• Solar


  Which energy resource isn't great in the UK as we don't get much Sun?
• Hydroelectric


  Which energy resource depends on falling water in dams?
• Tidal


  Which energy resource depends on the movement of water as a result of the pull of the moon?