p1 energy Flashcards
what is a system?
an object or group of objects
what are the main 4 examples of different stores of energy?
1) kinetic energy
2) elastic potential energy
3) gravitational potential energy
4) chemical energy
energy changes when a ball is thrown upwards?
1) Ke as the ball is going up
2) Ke is then all transferred to GPE when the ball reaches is maximum height.
3) GPE is then all transferred to Ke as the ball is falling back down
energy changes when a moving object hits an obstacle?
1) Ke at the time of collision
2) then transferred to thermal energy due to the particles in the objects vibrating + friction of collision AND sound energy
3) still Ke as the object may move away from the collision
energy changes in an object accelerated by a constant force
1) sound energy which is eventually transferred to thermal energy
2) Ke as the object accelerates
energy changes as a vehicle is slowing down?
1) decrease in Ke as the vehicle slows down
2) transferred to thermal energy due to the friction between the tires and ground.
3) sound energy
3) eventually, all the Ke is transferred to thermal energy, then potential energy when the vehicle fully stops
energy changes in boiling water?
1) electrical energy
2) converted to thermal energy and sound energy
equation for Ke?
0.5 x mass x (speed)^2
equation for EPE?
0.5 x spring constant x (extension)^2
equation for GPE?
mass x gravitational field strength x height
equation for change in thermal energy?
mass x specific heat capacity x temp change
equation for power?
1) energy transferred// time
2) work done// time
what is the law of the conservation of energy?
energy can not be created or destroyed, only transferred into different forms
how is energy dissipated in the system of a ball being thrown upwards?
thermal energy due to air resistance, causing friction between the ball and air particles
how is energy dissipated in the system of a moving object hitting an obstacle?
sound energy from the collision and thermal energy due to particles vibrating and friction between objects
how is energy dissipated in the system of an object accelerated by a constant force?
thermal energy when the objects rub together and possible sound energy
how is energy dissipated in the system of a vehicle slowing down?
thermal energy due to the friction between the tires and the ground
how is energy dissipated in the system of boiling water in a kettle?
thermal energy in the evaporation of the water
methods of reducing unwanted energy?
lubrication and insulation
what is the relationship between energy transfer through a material and the conductivity of that material?
the higher the conductivity, the higher the rate energy passes through
how to prevent heat loss in a building?
1) double glazing the windows
2) thickening the walls
3) loft and wall insulation
equation for efficiency
1) useful energy output// total energy input
2) useful power output// total energy input
how to increase efficiency?
decrease waste energy (through insulation or lubrication) OR use/ recycle the wasted energy
sources of renewable energy?
1) wind energy
2) hydro electric energy
3) tidal energy
4) solar energy
5) biofuel
6) geothermal energy
sources of non-renewable energy?
1) fossil fuels (coal, oil and gas)
2) nuclear energy
what is renewable energy?
energy that can be replenished as its being used
what are the uses of energy resources?
transport, electricity generation and heating
what energy resource(s) are mainly used for transportation?
biofuel
which energy resource(s) are mainly used for heating
gas, electric and geothermal
which energy resource(s) are mainly used for
hydroelectricity, nuclear energy, natural gas, wind energy, tidal energy and geothermal
why are non-renewable sources of energy more reliable than renewable energy?
1) quick start up
2) doesnt rely on external factors (eg wind)
3) can generate larger quantities of power when needed
impact of fossil fuels on the environment
(disadvantages)
1)production of CO2 into the air, greenhouse gas, contributing to global warming as it traps heat in our atmosphere
2) sulphur dioxide production, could cause acid rain, damaging buildings
disadvantage of using renewable energy?
1) output is determined by external factors
advantages of using fossil fuels as an energy resource?
1) reliable as they do not rely on external factors to generate energy
2)can produce large quantities of electricity when needed
3) cost-effective
advantages of nuclear power?
1) doesnt release greenhouse gasses
2) very large amounts of energy for little fuel
3) low fuel costs
disadvantages of nuclear power?
1) risks of nuclear explosions
2) non renewable
3) produces nuclear waste which is harmful to humans
disadvantages of using biofuel as an energy resource?
1) CO2 emissions
2) in order to grow biofuels, land must be destroyed
advantages of tidal energy?
1) do not produce greenhouse gasses
2) reliable as tides happen 2 times a day
3) very cheap to run
disadvantages of hydroelectricity?
1) dam might cause flooding
2)costs a lot to install the required infastructure
advantages of using solar power?
1) dont cause harm to the environment
2) are renewable
3)can be used in remote areas where other types of energy may not be accessible
examples of social factors that cause deterrence to certain types of energy production?
1) visual pollution
2) sound pollution
