P1 - Energy Flashcards
Name 8 stores of energy
Magnetic
Internal (thermal)
Chemical
Kinetic
Electrostatic
Elastic potential
Gravitational potential
Nuclear
Define magnetic energy
The energy stored when repelling poles have been pushed closer together or when attracting poles have been pulled further apart.
Define kinetic energy
The energy of a moving object.
Define internal (thermal) energy
The total kinetic and potential energy of the particles in an object, in most cases this is the vibrations - also known as the kinetic energy - of particles.
Define chemical energy
The energy stored in chemical bonds, such as those between molecules.
Define gravitational potential energy
The energy of an object at height.
What are the four types of energy transfers?
Mechanical work
Electrical work
Heating
Radiation
What is mechanical work?
A force moving an object through a distance.
What is electrical work?
The charges moving due to a potential difference.
What is heat?
Heat is the flow of kinetic energy from one object to another.
What is radiation?
Energy transferred as a wave.
What is the equation for kinetic energy?
1/2 x mass x velocity^2
What is the equation for elastic potential energy?
1/2 x spring constant x extension^2
What is the equation for gravitational potential energy?
Mass x GFS x height
What is the Specific Heat Capacity of a substance?
The amount of energy needed to raise the temperature of 1kg of a substance by 1 degree.
Define power.
The rate at which energy is transferred (work is done).
What is the equation for power?
Power = work done (energy transferred) / time
Describe the energy transferences for a bungee jumper.
When falling GPE is converted into KE of the jumper. As the cord tightens KE is transferred and stored as EPE. At the jumpers lowest point the amount of GPE at the jumpers highest point is the same as the EPE stored in the cord.
Explain why a bungee jumper slows down when the cord begins to stretch.
KE is converted into EPE and since KE is proportional to velocity squared as KE decreases so does velocity.
Give examples of chemical energy stores.
Food, fuel, batteries.