P1 (physic)(book) Flashcards
Generating electricity
What are the units for energy?
Joules
How many energy stores are there?
8
How many pathways are there?
4
Name the 4 pathways
give an example for each
Electrical (electricity)
Mechanical (forces)
Radiation (light and other waves)
Heating (temperature)
What is the conservation of energy?
Energy cannot be created or destroyed, it can only be transferred from one store to another
Define work
The energy required for a force to move an object
What is the equation for work?
Work=force x distance
Joules (J) = newton’s (N) x metres (m)
Name the 8 energy stores
Kinetic
Gravitational potential
Thermal
Elastic potential
Nuclear
Magnetic
Chemical
Electrostatic
Definition of kinetic energy
Energy of a moving object
Definition of gravitational potential Energy
Energy of an object at height
Definition of thermal Energy
Energy due to temperature
Definition of elastic potential Energy
Energy stored when a object is stretched or squashed
Definition of nuclear energy
Energy stored by the nucleus of an atom
Definition of chemical Energy
The energy stored in fuels
Definition of electrostatic energy
The energy stored when two charges interact with each other
Define power
The rate at which energy is transferred
The energy transferred (J) each second (s)
What is the equation to calculate power?
Power = energy ÷ time
(Watts) = (joules) ÷ (second)
Write the symbol equation for energy
E=P x t
What is the equation for total cost ?
Total cost = units of kWh used x cost per unit
Write the equation for gravitational potential energy
Ep = m x g x h
Gravitational potential energy = mass x gravitational field strength x height
What is the gravitational field strength on earth ?
9.8 N/kg
What is the gravitational field strength on the moon?
1.6 N/kg
Write the equation for kinetic energy
Kinetic energy = 0.5 x mass x velocity squared
Ek = 1/2 m v squared
Ek = 0.5 x m x v squared
If the mass doubles what happens to the kinetic energy ?
It also doubles
If the v doubles what happens to the kinetic energy?
Kinetic energy quadruples
What is Ek max equal to?
Ep max
What is the Ep max equal to?
Ek max
Define ‘efficiency’
The proportion of energy that is usually transferred in a process
State the factors to increase efficiency
Aerodynamics → reduce friction
Streamline for water →reduce friction
Lubrication → reduce friction
Insulation → reduce heat loss
Write the equations for efficiency
Efficiency = useful output energy transfer ÷ total energy transfer
Efficiency = useful output power ÷ total power
e=u ÷T
State 2 advantages from using solar
No CO2
Reliable
State 2 disadvantages from using solar
Doesn’t work at night
Take up a lot of space
What is meant by ‘kilowatt hour’
The energy used by something with a power of 1kw (1000W) in a time of 1 hour
The kinetic energy stored by an object depends on what 2 things?
The mass of the object (m)
The speed the object is moving at
The gravitational potential energy stored by an object depends on what 3 things?
The mass of an object (m)
The height the object is at (h)
The gravitational field strength around the object (g)
What is meant by ‘dissipation’?
Energy wasted during an energy transfer (almost always transferred to the thermal energy store of the surroundings)
What is the maximum possible efficiency? (As a percentage and as a number)
100% or 1
Should insulation have a high or low thermal conductivity?
Low
The lower it is the less heat it will conduct
What are the fossil fuels?
Coal
(Crude) oil
(natural) gas
What non-renewable energy source is not a fossil fuel?
Nuclear
What green house gases are released when fossil fuels are burnt?
Carbon dioxide
Sulphur dioxide
Nitrogen oxide
(Methane is released during coal mining)
What does ‘non-renewable’ mean?
It cannot be replenished / it will run out
What does ‘renewable’ mean?
It can be replenished/ it will not runout
Name 6 renewable energy sources
Solar
Wind
Geothermal
Hydroelectric
Tidal
Biomass
What are the units for velocity?
m/s
Is coal renewable?
Non-renewable
What is coal’s main use?
Electricity
State 2 advantages of using coal?
Cheap
Stores a lot of energy
State 2 disadvantages of using coal?
Releases CO2
Mining releases methane contributes to global warming
Is (crude oil) renewable?
Non- renewable
What is (crude) oil’s main use?
Transport (petrol etc.)
Give 2 advantages of using (crude) oil
Easy to store and transport
Stores a lot of energy (small amount of oil needed)
Give 3 disadvantages of using (crude) oil
Releases CO2
Oil spills can harm marine life
Lots of air pollution when burnt
Is (natural) gas renewable?
Non-renewable
What is (natural) gas’s main use?
Electricity & heating
Give an advantage of using (natural) gas
Releases less CO2 than coal or oil
Give 2 disadvantages of using (natural) gas
Release CO2
Can be dangerous (gas explosion)
Is nuclear renewable?
Non-renewable
What is nuclear’s main use?
Electricity
Give 2 advantages of using nuclear
No CO2 released
Very efficient (tiny amount of fuel needed)
Give 2 disadvantages of nuclear
Produces nuclear waste
Very expensive (to run and to dispose of waste)
Is solar power renewable?
Renewable
What is solar power’s main use?
Electricity
Name 3 advantages of using solar power
No CO2 released
Not much Maintenance needed
Can be placed in remote locations
Name 3 disadvantages of using solar power
Only works during the day
If light is low, they don’t generate much electricity
Solar panels take up large space
Is wind turbine renewable?
Renewable
What is wind turbine’s main use?
Electricity
Give 2 advantage of using wind turbine
No CO2 released
Can be placed in remote locations
Give 3 disadvantages of using wind turbine
Unreliable- its not always windy
Noise and visual pollution
Can kill birds
Is hydroelectric (a dam) renewable?
Renewable
What is hydroelectric (a dam) ‘s main use ?
Electricity
Give 3 advantages from using hydroelectric (a dam)
No CO2 released
Can generate electricity 24 h a day
very quick start time
Give 3 disadvantage of using hydroelectric (a dam)
Expensive
Visual pollution
Can cause flooding
Is tidal renewable?
Renewable
What is tidal’s main use?
Electricity
Give 3 advantages of using tidal
No CO2 released
Can generate electric 24h a day
Very quick start time
Give 2 disadvantages of using tidal
Expensive
Can damage sea-life
Is geothermal (volcanic heat) renewable?
Renewable
What is geothermal (volcanic heat) ‘s main uses?
Electricity
Heating
Give 2 advantages of geothermal (volcanic heat)
No CO2 released
No fuel costs
Give 2 disadvantage of geothermal (volcanic heat)
Only available in limited areas where there is sufficient heat underground
These ares can be dangerous (near volcanoes)
Is biomass (burning wood) renewable?
Renewable
What is biomass (burning wood) ‘s main uses?
Electricity
Heating
Give 2 advantages of using biomass (burning wood)
Waste products can be turned into biofuel
Renewable - plants can be grown quickly for biofuel
Give 2 disadvantages of biomass (burning wood)
New forests have less biodiversity
Creates air pollution when burned
Which resources impacts global warming and what is the explanation?
Coal
Oil
Gas
Combustion of fossil fuels releases carbon dioxide , greenhouse gas
Mining coal also releases big quantities of methane, a more powerful greenhouse gas
Which resources impact acid rain and what is the explanation to it ?
Coal
Oil
Gas
Sulphur and nitrogen get are released when burning fossil fuels, producing sulphuric acid and nitric acid in clouds
Which resource impacts the loss of habitats and what is the explanation to it?
Coal
Mining coal causes the destruction of large natural areas
Which resource impacts oil spills and what is the explanation?
Oil
Failures in oil rigs can cause massive spills into the ocean, damaging marine life
