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