Physics Chapter 1 Energy Transfers Flashcards
What is a system?
A system is an object or group of objects.
What is a closed system?
A system where energy cannot enter or leave.
In terms of energy, what happens when a system changes?
Energy must transfer from one store to another along an energy pathway.
What are the units of energy? (Units and Symbol)
Joules (J)
State the 8 energy stores
Gravitational Potential Energy (GPE)
Kinetic Energy (KE)
Elastic Potential Energy
Thermal (Internal)
Chemical
Magnetic
Electrostatic
Nuclear
Describe how the gravitational potential energy store can increase or decrease.
Increase - Object raised higher above ground (higher in gravitational field)
Decrease - Object lowered (closer to centre of gravitational field)
Describe how the kinetic energy store can increase or decrease.
Increase - Object speeds up (or becomes heavier)
Decrease - Object slows down (or becomes lighter)
Describe how the elastic potential energy store can increase or decrease.
Increase - An object is stretched or squashed (deformed) in such a way that it would return to its original shape if the force was removed.
Decrease - The size of the deformation is reduced, so the object is closer to its original shape.
Describe how the thermal (internal) energy store can increase or decrease.
Increase - Increase in temperature or a change of state (solid→liquid→gas)
Decrease - Decrease in temperature or a change in state (gas→liquid→solid)
Describe how the chemical energy store can change.
Through chemical reactions.
Describe how the magnetic energy store can change.
Changes to the strength, or location within a magnetic field.
Describe how the electrostatic energy store can change.
Transfer of charges or changes to an electric field.
Describe how the nuclear energy store can change.
Changes in the nucleus of atoms.
Give an example of a chemical energy store.
Fuel
Food
Batteries
State the principle of conservation of energy.
Energy cannot be created or destroyed, only transferred from one store to another along an energy pathway.
Name the four energy pathways.
Mechanical (Forces)
Radiation (Waves)
Electrical
Heating
What is work done.
A measure of energy transferred.