T1 - Energy Flashcards
What is a system?
Object or group of objects
What is a closed system?
Systems where energy cannot leave or enter
Equation for kinetic energy?
Kinetic energy = 0.5 × mass(kg) x speed^2(m/s)
Equation for elastic potential energy?
Elastic potential energy = 0.5 × spring constant(N/m) × extension^2(m)
Equation for gravitational potential energy
Gravitational potential energy = mass(kg) × gravitational field strength(N/kg) × height(m)
What is specific heat capacity?
The amount of energy required to raise the temperature of 1kg of the substance by 1 degrees C
Equation for change in thermal energy?
Change in thermal energy = mass(kg) × specific heat capacity(J/kg C) × temperature change(C)
What is power?
The rate at which energy is transferred or the rate at which work is done.
What are the equations for power? x2
Power(W) = Energy transferred(J)/time(S)
Power(W) = work done(J)/time(S)
What can and cannot energy do?
Energy can be transferred, stored or dissipated, but cannot be created or destroyed.
What is work done?
Energy transfer from one store to another
Work done equation?
Work done(J) = Force(N) x Distance(m)
What are the equations for efficiency? x2
Efficiency = energy output/energy input
Efficiency = power output/power input
What are the uses of energy? X3
Transport, generating electricity and heating.
What are the three fossil fuels?
coal, oil and gas
Advantages of fossil fuel? x4
- Reliable
- releases lots of energy
-abundant and cheap - Versatile
Disadvantage of fossil fuels? x3
-Releases a lot of carbon dioxide
-Releases other harmful pollutants
- They are non-renewable
What is a renewable energy source?
An energy source that is being replenished as it is used
Advantages of renewable energy resources? x2
-Never run out
-Not bad for environment
Advantages of wind and solar power? x2
-low running costs
-Doesn’t damage environment
disdvantages of wind and solar power?
-unreliable
Advantages of hydroelectric power?
-Reliable
Disadvantages of hydroelectric power? x2
-Habitats are destroyed and valleys are flooded
- Needs lots of rivers
Advantage of tidal power?
-reliable
Disadvantage of tidal power?
High set up costs
Advantage of geothermal energy?
Only damages the environment slightly
Disadvantage of geothermal energy?
-Only in volcanic regions
- Can be expensive
What are biofuels?
Fuels made from recently living organisms
Advantages of biofuels? X4
-renewable
-cheap to make
-easy to transport
-Can be mixed with fossil fuels
Disadvantages of biofuels? X2
-Require lots of energy
-Need somewhere to grow plants
