Energy

HideShow resource information
• Created by: lh1002
• Created on: 16-05-16 17:47
What are the 9 different types of energy?
Thermal, Kinetic, Elastic Potential, Light, Sound, Nuclear, Chemical, Gravitational Potential, Electrical
1 of 44
Do energy transfer diagrams only show useful energy, wasted energy or both?
Useful energy
2 of 44
What is the spring constant? (k)
k= 25 N/m
3 of 44
What is the equation for gravitational potential energy? Include units.
Gravitational potential energy (in J)= mass (in kg) x gravitational field strength (10N/kg) x change in height (m)-- (GPE= mgh)
4 of 44
What is work done?
The work done on an object to get it to move.
5 of 44
What is the equation for work done?
Work done (in J) = force (in N) x distance moved (m)-- (W=Fs)
6 of 44
What is 1 Watt the same as?
1 Joule per second
7 of 44
What is 1 Joule the same as?
1 Nm
8 of 44
What is the equation for power? Include units.
Power (in W)= work done or energy (in J) / time (in s)
9 of 44
What is specific heat capacity?
A measure of the amount of energy required to raise the temperature of 1kg of a material by 1'C
10 of 44
What is the equation for specific heat capacity? Include units.
Energy supplied (in J)= mass (in kg) x specific heat capacity (in J/kgK or J/kgC) x temperature difference (K or C)
11 of 44
Name 4 types of insulation for a house.
Carpets, double glazing, cavity wall insulation, loft insulation (fibreglass), insulation jacket, floor insulation (carpets), draught excluders etc.
12 of 44
What is the definition of efficiency?
A measure of how much energy is transferred in a useful way.
13 of 44
What is the equation for efficiency?
Efficiency= useful energy output/total energy input x 100%-- (Eo/Ei x 100%)
14 of 44
In a sankey diagram: 1- Where is the input energy? 2- Where is the useful energy and what direction is it facing? 3-Where is the wasted energy and what direction is it facing?
1- the left of the useful and wasted energy, 2- above the wasted and right of the input energy, and is facing right, 3- below the useful and right of the input energy, and is facing down
15 of 44
What are the 9 main energy sources?
Solar, wind, tidal, hydroelectric, biomass, wave, geothermal, nuclear, fossil fuels
16 of 44
ADVANTAGES: cheap,doesn't produce as much pollution as fossil fuels, DISADVANTAGES: risk of major accident, produces waste which needs disposing
17 of 44
ADVANTAGES: reliable, flexible in meeting demand, DISADVANTAGES: fuel will eventually run out, lots of pollution
18 of 44
What is conduction?
The process of where vibrating particles pass on extra kinetic energy to neighbouring particles. Conduction only occurs in solids.
19 of 44
Describe the process of conduction.
Electrons in metal leave their atoms & move as free electrons. The atoms left are now + metal ions & are close together & they vibrate. The hotter the metal, the more they vibrate. KE is transferred to cooler parts by electrons that collide with ions
20 of 44
What is convection?
When the more energetic particles move from the hotter region to the cooler region and take their heat energy with them. Convection only occurs in liquids and gases.
21 of 44
Describe the process of convection.
The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas. The denser cold liquid or gas falls into the warm areas.
22 of 44
Why do liquids and gases expand when they are heated?
The particles in liquids and gases move faster when they are heated than they do when they are cold. As a result, the particles take up more volume. This is because the gap between particles widens, while the particles themselves stay the same size.
23 of 44
The transfer of heat energy by electromagnetic radiation
24 of 44
If an object is hotter, will it give out more or less infrared radiation?
More
25 of 44
What surfaces are good and bad for absorbing and emitting infrared radiation?
Dull surfaces are good absorbers and emitters of infrared radiation. Shiny surfaces are poor absorbers and emitters (but they are good reflectors of infrared radiation).
26 of 44
What is used to stop heat energy transfers from buildings and the human body?
Insulation
27 of 44
Energy carried by particles from a radioactive substance, or spreading out from a source
28 of 44
What are insulators?
Materials that have few or no free electrons so they can't transfer energy by heating
29 of 44
What is power?
The power rating of an appliance is defined as 'the rate of doing work' or 'the rate of transferring energy'
30 of 44
Describe what happens when generating wind energy and give one advantage and one disadvantage of it
As the wind blows, it transfers some of its KE to the blades which then turn and generates electricity, ADVANTAGE: renewable energy source, DISADVANTAGE: The amount of electricity generated depends on the strength of the wind.
31 of 44
Describe what happens when generating hydroelectric power and give one advantage and one disadvantage of it
Water high up behind a dam has GPE. This is transferred to KE as the water rushes down through tubes inside the dam. The moving water drives electrical generators. ADVANTAGE: renewable, DISADVANTAGE: can flood farmland and push people out of homes
32 of 44
Describe what happens when generating wave power and give one advantage and one disadvantage of it
Wave machines use the kinetic energy in the movement of waves to drive electricity generators. ADVANTAGE: no pollution, DISADVANTAGE: It has been difficult to scale up the designs for wave machines to produce large amounts of electricity.
33 of 44
Describe what happens when generating tidal power and give one advantage and one disadvantage of it
A tidal barrage is a barrier built over a river estuary to make use of the KE in moving water. These contain electricity generators, which are driven by the water rushing through tubes. ADVANTAGE: reliable, DISADVANTAGE: destroys the habitat
34 of 44
Describe what happens when generating geothermal energy in volcanic areas and give one advantage and one disadvantage of it
Radioactive decay of some substances releases heat energy, this warms up rocks. In volcanic areas, rocks may heat water so it rises naturally as it turns to steam and turns a turbine, ADVANTAGE: no fuel costs, DISADVANTAGE: few places where available
35 of 44
Describe what happens when generating geothermal energy in non volcanic areas
Sometimes the rocks are hot but no hot water or steam rises. Instead, deep wells are drilled down to the hot rocks and cold water pumped down. The water runs through fractures in the rocks and is heated up. It returns as steam which turns a turbine
36 of 44
Describe what happens when generating solar energy in solar cells and give one advantage and one disadvantage of it
Solar cells convert light energy directly into electrical energy. ADVANTAGE: renewable, DISADVANTAGE:expensive and inefficient- cost of their electricity is high, don't work at night
37 of 44
Describe what happens when using solar energy in solar panels
Cold water is pumped up to the solar panel, it heats up and is transferred to a storage tank. A pump pushes cold water from the storage tank through pipes in the solar panel. The water is heated by heat energy from the Sun and returns to the tank.
38 of 44
What do solar panels do and give one advantage and disadvantage of them.
They heat up water. ADVANTAGE: renewable, no pollution, DISADVANTAGE: may only produce very hot water in very sunny climates, and in cooler areas may need to be supplemented with a conventional boiler, don't work at night
39 of 44
Describe what happens when generating nuclear power
In nuclear power stations, nuclear fuel has a controlled chain reaction in the reactor to produce heat- the energy is converted to heat energy: heat changes water into steam, this drives the turbine, which drives the generator to produce electricity
40 of 44
Give examples of biomass fuels, how it is used to make heat and one advantage and disadvantage
Fuels include wood, straw, manure, sugar cane, to make heat you can burn the fuels directly, ADVANTAGE: If replaced, biomass can be a long-term, sustainable energy source, DISADVANTAGE: only renewable if crops are replanted
41 of 44
Describe how electricity from fossil fuels is made
The fossil fuels release heat when they burn which turns water into steam. This rises and turns a turbine which drives the generator and creates electricity
42 of 44
What is the equation for elastic potential energy? Include units.
Stored elastic potential energy (in J)= 0.5 x spring constant (25 N/m) x extension ² (in m)-- (stored EPE= 0.5 k e ²)
43 of 44
What is the equation for kinetic energy? Include units.
Kinetic energy (in J) = 0.5 x mass (in kg) x speed ²(in m/s)-- (KE= 0.5mv ²)
44 of 44

Other cards in this set

Card 2

Front

Do energy transfer diagrams only show useful energy, wasted energy or both?

Useful energy

Card 3

Front

What is the spring constant? (k)

Card 4

Front

What is the equation for gravitational potential energy? Include units.

Card 5

Front

What is work done?