Flashcards in Topic Three- Energy Deck (13):
What are the types of energy - give an example of an object that has each type?
Kinetic ( moving car), heat (light bulb), light ( it cannot be stored but light bulb), gravitational potential ( book on shelf), chemical (humans), sound ( cannot be stored but speaker), electrical (appliances), elastic potential( a pulled rubber band), and nuclear (bombs)
What is the principle of energy conservation?
Energy can neither be created or destroyed, only transferred.
What are the three categories of energy transfers and what decides the two types of output energies?
Input, output and waste. The empirical experience of the characteristics decides if it is either waste or useful ( if it is required for the purpose).
What is the diagram that shows energy transfers and what is important about the width of the arrows?
A Sankey diagram.
Both arrows must equal the width of the total energy imputed.
What is the equation for efficacy?
Efficacy = useful output energy divided by total input energy x 100 %
What does it mean if a filament light bulb is less efficient than an energy saving lightbulb?
It means that the total percentage of useful energy in a filament lightbulb is smaller than in an energy efficient one.
What are the two ways of minimising energy wasted in a mechanical system?
Lubrication - The reducing of friction that reduced both heat loss and wear and tear in moving parts.
Insulation - Heat loss through cavity wall insulation. This involves blowing insulation material into the gap, reducing heat loss through conduction.
What is the equation of kinetic energy?
Kinetic energy = 1/2 x mass x velocity squared
Mass(kg) velocity (m/s)
What is the equation for gravitational potential energy?
Gravitational potential energy = gravitational field strength x mass x height ( GPE = G x M x H )
Gravitational potential energy = weight x height ( GPE = W x H)
What are the energy resources( ways if generating energy )?
Hydro electrical, geothermal, fossil fuels, wind, solar, waves, biomass, nuclear, tidal.
What are the advantages and disadvantages renewable energy resources?
Expensive for original purchase
Engineers have to take into consideration bird migration routes.
Renewable advantages :
Relatively cheap to run once bought
Can be reliable e.g. tidal
What are the disadvantage and advantages of non- renewable energy resources?
Non-renewable Advantages :
Easy to transport
Bad for the environment
Slowly running out - Consumption is quicker then manufacture
Dangerous to dispose of