P1: Energy Flashcards
Law of conservation of energy?
Energy cannot be created or destroyed it can only be transferred from one store to another
Energy stores? (8)
GRAVITATIONAL POTENTIAL:when they are lifted through a gravitational field
KINETIC: moving objects
ELASTIC: squashed bent or stretched
MAGNETIC: energy from magnetic attraction
ELECTROSTATIC: objects with a charge interacting
CHEMICAL: chemical reactions
NUCLEAR: atomic nuclei
THERMAL: hot objects
Energy pathways (4)
MECHANICAL: when a force acts on an object
ELECTRICAL: a charge moving through a potential difference
HEATING: transferred from a hotter object to a colder one
RADIATION: electromagnetic waves
What is wasted energy?
Energy that is not useful for the intended purpose and is dissipated into the surroundings
What is useful energy?
Energy that is transferred from store to store and used for an intended purpose
2 ways to prevent wasted energy?
Lubrucation: friction can cause dissipation and lubrication prevents friction
Insulation: energy is prevented from dissipating
What is efficiency?
The ration of the useful energy output from a system to its total energy output
4 ways to improve the efficiency of a system?
Reducing friction
Reducing electrical resistance (reducing current or using components w less resistance)
Reducing air resistance (streamlining)
Reducing noise
Renewable energy sources (6) pros and cons
SOLAR: ✅no pollution ,renewable❌only in sunny weather, expensive
WIND✅no pollution, no burning, cheap and easy to build turbines, low income countries❌only in windy weather, ugly and noisy
GEOTHERMAL: ✅no pollution ❌expensive, only a few places in the world where it can happen
BIOMASS/FUEL: ✅doesn’t need soecial equipment, planting trees❌ large ares of land needed
WAVES: ✅no pollution❌needs machines, not appealing (looks), damages by weather
TIDAL ✅reliable, cheap❌dam is expensive, dam could cause flooding
Non renewable energy resources(2) pros and cons
NUCLEAR: ✅doesn’t produce co2 or so2, 1kg of fuel produces, a lot!❌costs a lot, accident can be catastrophic , dangerous and radioactive
FOSSIL FUELS :coal, oil, gas ✅cheap and easy, most inventions are designed to run on fossil fuels, versatile ❌releases so2 (acid rain) releases co2 (greenhouse effect)
What are the waste products of burning fossil fuels and what problems do they cause?what can we do to prevent these problems?
CO2: global warming (plant trees)
SO2: acid rain, destroys habitats( use coal w less sulphur)
NITROGEN OXIDES: lung infections, vegetation (use fuels that have less nitrogen)
PARTICULATES: reduce visibility and cause a fog and global dimming (drive less)
What is the waste product of nuclear energy resource and what problems does it cause?what can we do to prevent these problems?
NUCLEAR WASTE: very dangerous can be catastrophic if not disposed safely (evaporate liquid waste
