Topic 1 and Topic 2- Energy and Energy Resources, Energy transfer by heating Flashcards
What does G-E-E-K-S
L-U-N-C-H stand for? (u does not stand for anything)
- Gravitational potential energy
- Electrical energy
- Elastic energy
- Kinetic energy
- Sound energy
- Light energy
- Nuclear energy
- Chemical energy
- Heat (thermal) energy
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transformed into another type of energy
What is the formula for Kinetic energy and what it measured in?
Kinetic energy is measured in Joules, and the formula is [Ek = 1/2 x m x v(squared)
What is wasted energy?
Wasted energy is any energy the comes out of a situation that we didn’t intend it to be there.
For example, In a light bulb, it generates light, heat and sound. The heat and sound is wasted, or is dissipated into the surroundings.
What kind of insulation can you put into a house for it to be more energy efficient?
- Cavity wall insulation
- Double glazing
- Loft insulation
- Carpet
- Curtain
- Draft excluders
- Jacked around hot water tank
What is the formula for efficiency?
Efficiency = Useful energy out/ total energy in
What are the 2 types of sources of Electricity?
Renewable sources and Finite sources
Name some Renewable sources:
Sun
Wind
Water - Tidal
Hydro-ep
Wave
GeothermalWhat are the advantages/ disadvantages of renewable sources?
The advantage of the majority of the renewable sources is that they don’t release carbon dioxide, we are never going to run out of them and they are usually non-polluting.
What are disadvantages to solar energy?
Disadvantage of solar is that it can be expensive to install and isn’t very effective during cloudy days, Wintery days and during Night.
What are disadvantages to Wind Turbines?
Some people do not like wind turbines. They also don’t work very well during non-windy days.
What is a disadvantage to tidal and wave power?
Can be disruptive to the local environment
What is a disadvantage to a hydro-electric dam?
Involves flooding a large area which many include people’s homes or anima’s habitats
What is a disadvantage to Geothermal power?
It can only be used in volcanic areas.
What are the advantages of using fossil fuels or nuclear power?
They are readily available and it’s a cheap source of electricity, and things like coal power stations have a short start up time
What is the disadvantage of using coal, oil and gas?
They take millions and millions of years to create. (we are about to run out of them)
They are very heavily polluting (releases large amounts of carbon dioxide into the atmosphere which contributes to climate change)
What is the disadvantage of nuclear power?
You have to store nuclear radioactive waste for long periods of time
There is a very small but potential risk of explosion
What does energy transferred also equal to?
Work done
What is work done?
When an object is moved by a force.
If 20J is the work you do on an object to lift it up, how much will that go to Gravitational potential energy?
20J
What is the equation for work done?
Work done (W) = Force applied (F) X Distance moved along the line of action of the force (s)
What is Force applied measured in?
Newtons (N)
What is Work done measured in?
Joules (J)
What is distance moved along the line of action of the force measured in?
Metres (M)
Imagine a lorry over 40m. On the level ground, 2000N is needed. How much is the work done?
80kJ (40X2000)
What is change in object’s gravitational potential energy stores measured in?
change in object’s gravitational potential energy stores
= Weight (N) X change of height (m)
What happens to an object’s gravitational potential energy when it is moved up?
The energy in its gravitational potential energy store increases.
What happens to an object’s gravitational potential energy when it is moved down?
The energy in its gravitational potential energy store decreases.
What is the equation for change of gravitational potential energy store?
Mass (Kg) x Gravitational field strength (newtons per kilogram) x Change of height (metres)
What is the equation for kinetic energy?
1/2 x Mass x Speed [squared] (metres per second, m/s) [squared]
How do you find the spring constant?
You do Force divided by change in spring length (f/x)
What is the equation for elastic potential energy?
1/2 x spring constant (Newtons per metre, N/m) x Extension [squared] (metres squared)
What is Useful energy?
Useful energy is energy transferred to where it is wanted in the way that is wanted.
What is the equation for weight?
weight = mass x gravitational field strength
W = mg
What does the energy transfer per second through layer of insulating material depend on?
The temperature difference across the material
The thickness of the material
The thermal conductivity of the material
What can you do to reduce the energy transfer (of insulating material) in any given possible situation?
The thermal conductivity of the insulating material should be as low as possible.
The thickness of the insulating material should be as low as possible.
What are the 4 transferred energy stores?
Mechanically: like physically stretching an elastic band
Heating: Heating
Electrically: Like plugging something into a socket
Radiation: Light or sound waves
How can you describe kicking a ball in energy stores?
Chemical energy store > transferred > kinetic energy store
What is a kinetic energy of an object?
Energy that it posses due to its motion.
What 2 things depend on how much kinetic energy an object has?
Its Speed - Faster: more kinetic energy
Its Mass - More: more kinetic energy
If a plane is 20 tonnes and goes at a speed of 5 m/s, how much kinetic energy does it have?
250,000 Joules or 250kj
If a particle is 0.1 grams and is going at a speed of 4000 m/s, how much kinetic energy does it have?
800 Joules or 0.8kj
What is gravity?
A force of attraction between two objects
What 2 things depend on how much gravitational energy an object has?
Mass and how far apart those objects are
What is the gravitational field strength for Earth?
9.8 newtons / Kg
