P1 Energy Flashcards
What does it mean if an energy resource is reliable?
It it predictable
What happens when a forces moves an object?
Work is done which is another way of saying energy is transferred.
The amount of work done/ energy transferred depends on the size of the force and distance the object moves.
What is a renewable energy resource?
One that can be replenished as it is used.
e.g. solar, wind
Why might people not like having wind turbines near their homes?
Visual pollution
Noise pollution
Dangerous to birds
Explain how thick cavity walls reduce unwanted energy transfers.
The wall has a low thermal conductivity so the rate of energy transfer is lower.
Which equations link energy transferred, power and time
Energy transferred = Power x time
Power = Energy transferred / time
What are the uses of energy resources?
Heating
Transport
Electricity generation
Give examples of non-renewable energy resources.
Fossil fuels (coal, oil and gas)
Nuclear
Give examples of renewable energy resources.
bio-fuel (such as wood)
solar
wind
tidal
hydroelectricity
geothermal
What are the environmental impacts of using fossil fuels for transport and to generate electricity?
Release carbon dioxide → increases global warming
Release sulphur dioxide and nitrogen oxide → increases acid rain
Release particulates → causes global dimming
Give the advantages and disadvantages of bio-fuels.
Providing land to grow crops for bio-fuels has led to deforestation.
Burning bio-fuels causes air pollution.
Bio-fuels are carbon neutral because the amount of carbon dioxide released when the fuel is burned is equal to the amount absorbed by the plants as they grow.
What does it mean if an electrical device is powerful?
Transfers lots of energy in a short space of time
Can energy be created or destroyed?
No, energy can be stored or transferred (either usefully or non-usefully).
How do you calculate efficiency?
Efficiency = useful power output / total power in
Efficiency = useful energy out / total energy in
What unit is power measured in?
Watts (W)
What unit is work done measured in?
Joules (J)
Give two way of reducing unwanted energy transfers.
Lubrication to reduce the amount of friction.
Thermal insulation to reduce the rate of energy transfer by heating
When a fuel is burnt which of its energy stores is emptied?
Chemical
When an object speeds up which of its energy stores is filled?
Kinetic
When an object slows down which of its energy stores is emptied?
Kinetic
When an object heats up which of its energy stores is filled?
Thermal
When an object cools down which of its energy stores is emptied?
Thermal
When a object is raised higher above the ground which of its energy stores is filled?
Gravitational potential
When an object is lower towards the ground which of its energy stores is emptied?
Gravitational potential
When a spring is stretched which of its energy stores is filled?
Elastic potential
Modern houses have walls and roofs with a low thermal conductivity. Explain why.
The walls and roof are better insulators so the rate of energy transfer is lower so less energy is needed to heat the house.
When a battery is charged which of its energy stores is filled?
Chemical
Eventually where does most energy end up?
Thermal energy store of the surroundings
With the exception of an electric heater no device is 100 % efficient. What does this mean?
Some energy is wasted, it is transferred to useless energy stores (usually thermal energy stores)
What are the energy transfers when a candle burns?
Chemical energy store of the candle decreases
Thermal energy store of the candle and the surroundings increases
What are the energy transfers when a catapult fires a stone?
Elastic potential energy store of the catapult decreases
Kinetic energy store of the stone increases.
Thermal energy store of the stone and surroundings increases.
What are the energy transfers when a skier goes straight down a hill
Gravitational potential energy of the skier decreases
Kinetic energy store of the skier increases.
Thermal energy store of the skier and surroundings increases.
What are the energy transfers when boiling water using a gas stove?
Chemical energy store of the gas decreases
Thermal energy store of the pan, water and surroundings increases.
How do you convert kilonewtons (kN) into newton’s (N)?
x1000
What are the energy transfers when the child lands on the trampoline?
Gravitational energy of the kid decreases
Kinetic energy of the child increases and then decreases to zero
The elastic potential energy of the springs increases
The thermal energy of the surroundings increases
