7I - Energy and food Flashcards
From where do our bodies get the energy they need?
From the chemical energy stored in food.
What is the unit for measuring energy?
Joule (J)
Why do we use kilojoules (kJ) instead of joules to measure the amount of energy in food?
There is a lot of energy stored in food.
how many joules in 1 kilojoule?
1000 J
What 5 things can transfer energy?
- Heat
- Light
- Sound
- Electricity
- Forces
How is the energy stored in food, fuels and batteries called?
Chemical energy
How is the energy stored in moving objects called?
Kinetic energy
How is te enrgy stored in hot objects called?
Thermal energy
How is the energy stored in objects that are stretched, squashed or twisted called?
elastic potential energy
(sometimes called strain energy)
How is the energy stored in objects that are moved to high places called?
Gravitational potential energy
How is the energy stored inside the particles that everything is made from called?
Nuclear energy
(sometimes called atomic energy)
What does the law of conservation of energy state?
Energy is not used up. It can be transferred or stored in different ways, but it cannot be created or destroyed.
What is a fuel?
A substance that stores energy and releases this energy when it burns.
(i.e. coal, wood, oil)
What are fossil fuels made out of?
plants and animals that died and got trapped in mud and rocks millions of years ago.
Name the three fossil fuels
Oil, coal and natural gas.
Are fossil fuels renewable? Why?
No. They take millions of years to form.
What do the gases produced when fossil fuels are burnt cause?
Pollution and global warming
Are fossil fuels cheap or expensive?
Are relatively cheap to obtain.
What was the original source of energy for fossil fuels?
The sun. Plants got their energy from the sun and animals got their energy from eating plants, which got their energy from sun.
Is nuclear fuel renewable? Why?
Is non-renewable. Nuclear power stations produce dangerous waste materials.
Is electricity a fuel?
No. It has to be generated by using other energy sources.
What can be done to reduce the usage of fossil fuels?
- Walking or cycling instead of using the car.
- Using public transport instead of cars.
- Keeping our houses cooler or keeping us warm with more clothes instead of heating.
Name the 7 types of renewable energy
- Solar
- Wind
- Tidal
- Wave
- Biofuels
- Geothermal
- Hydroelectricity
What are the advantages of using renewable energy resources?
- Do not produce harmful gases or contribute to pollution.
- Will not run out
What are the disadvantages of using renewable energy resources?
- Are not always availabe (i.e. solar energy is only available when there’s sun)
- Are often more expensive than fossil fuels.
Describe the availability of hydroelectricity, geothermal energy and biofuels
Are pretty much always available.
Describe the availability of tidal power
Is not always available, but we can predict when it will be.
Describe the availability of solar, wind and wave energy
Not always available
What are the only types of power that do not depend originally from the sun?
Geothermal, Nuclear and tidal power.
