particularly Flashcards
(28 cards)
What are the different types of energy stores?
- Thermal
- Kinetic
- Gravitational Potential
- Elastic Potential
- Chemical
- Magnetic
- Electrostatic
- Nuclear
These are the fundamental energy stores relevant in physics.
What are the methods of energy transfers?
- Mechanical
- Thermal
- Electrical
- Radiation (Light)
- Sound
Energy can be transferred in various forms, each with specific applications.
Define a system in the context of physics.
A group of objects that interact.
What does work done mean in relation to energy?
Energy is transferred; WD = Force x Distance.
What is the principle of conservation of energy?
Energy can be transferred but not created or destroyed.
What happens to energy during transfers?
Some energy is wasted/dissipated, most commonly as thermal energy.
What is the total energy in a closed system?
It will be constant even if energy is transferred between different stores.
What is kinetic energy?
Energy possessed by a moving object.
How is kinetic energy calculated?
KE = 0.5 x mass x velocity squared; KE = 1/2 mv.
What happens to gravitational potential energy (GPE) when an object is lifted?
It gains gravitational potential energy.
How is gravitational potential energy calculated?
GPE = mass x gravitational field strength x vertical height; GPE = mgh.
What is elastic potential energy?
Energy stored when a spring is stretched or compressed.
What is the specific heat capacity (SHC)?
The amount of energy required to raise the temperature of 1 kg of a material by 1°C.
How is specific heat capacity calculated?
SHC = energy / (mass x temperature change); c = E/mΔT.
What does power measure in physics?
The rate at which energy is transferred or the rate at which work is done.
How is power calculated?
- Power = Energy / Time
- Power = Work Done / Time.
What is conduction?
The transfer of thermal energy through particles that are in contact.
What is convection?
The transfer of energy through the movement of particles from hotter to cooler regions.
What is efficiency in a system?
The proportion of energy that is transferred usefully.
How is efficiency calculated?
- Efficiency = useful energy output / total energy input
- Efficiency = useful power output / total power input.
How can efficiency be expressed?
As both a decimal and a percentage.
What are some renewable energy sources?
- Biomass/Biofuels
- Solar
- Wind
- Geothermal
- Hydroelectric.
What is the role of fossil fuels?
Commonly used for generating electricity, transport, and heating.
What is geothermal energy used for?
Heating water to make steam to drive turbines or to heat buildings directly.
