Physics: Paper 1 Flashcards
What is the equation for Kinetic Energy
1/2 x mass x velocity^2
Elastic Potential energy
1/2 x spring constant x extension^2
Gpe
mass x gravitational field strength x height
Gravitational field strength on earth
9.8 N
Specific Heat Capacity (J/C/kg)
The amount of energy needed to raise the temperature of 1kg of a subsatance by 1 deg
Power (Watt (W))
The rate at which energy is transferred
power = work done/time
power = energy transferred/time
Chemical energy stores
Food
Fuel
Batteries
Law of energy conservation
Energy cannot be created or destroyed
Waste energy
Energy that is not used by the device for its desired purpose
Efficiency
= Useful output/ total output
How can efficiency be increased?
Reducing waste output - lubrication, thermal insulation
Recycling waste output
What is a renewable energy source?
an energy source that can be replenished as it is being used up
Examples of renewable energy
Wind
Hydro-electric
Tidal
Solar
Advantages of generating power using gas rather than coal
Gas power stations have shorter start-up times
Lower emissions of CO2
Disadvantages of using renewable energy
Supply is uncertain as it relies on external factors
Often economically beneficial to generate power through other means
Environmental impact of burning fossil fuels
CO2 contributes to the greenhouse effect, and causes global warming
Sulphur Dioxide leads to acid rain
Advantages of fossil fuels as an energy resource
Reliable
Can produce large amounts
Cost-effective
Advantages of nuclear power
Large amounts of energy from small quantities of fuel
Doesn’t release greenhouse gases
Low fuel costs
Disadvantages of nuclear power
Produces nuclear waste
Non renewable
Risk of nuclear accidents
How does hydroelectric power produce energy
Rainwater collects behind a dam
When this water is released, it is used to turn a turbine
Turbine turns a generator which produces electricity
Disadvantages of using biofuels
Releases CO2
Reduces land available for growing food
Advantages of tidal energy
No greenhouse gas production
Reliable as tides happen twice a day
Cheap
Disadvantages of hydroelectric power
Dam may cause flooding
expensive
Advantages of Solar panels
No harm to environment
Renewable
Can be used in remote areas
