Science Unit C Sec 3&4 Flashcards
(34 cards)
What is solar energy?
Energy given off by the sun
What are natural sources of thermal energy?
Sun, geysers, fire, decayed material
What 2 types of solar heating are there?
Passive heating or active heating
Explain passive solar heating
This means insulating a building as much as possible and placing windows where the sun shines in. It is when a building is made to collect and distribute solar energy.
What are some things that can let radiant energy in but not let it reflect back?
Extra panes of glass and special wall coating
What is Active Solar Heating
Active solar heating systems use solar energy to heat a fluid – either liquid or air – and then transfer the solar heat directly to the interior space or to a storage system for later use
How can solar energy be converted into energy?
Solar panels collect the Suns energy and stores it in batteries
What are some benefits of solar energy?
•It doesn’t create pollution
•
What is a thermostat?
They help us live comfortably by controlling the temperature in our environment
What is the average indoor temperature?
20C
How does a thermostat work?
It has a strip of 2 metals combined. When they heat up one of the metals expands faster than the other. This makes the metal bend. The bend is measured and if changes are needed in temperature it turns up or down the heat.
What 2 types of heating systems are there?
Local seating systems
Central heating systems
Explain local heating systems
They provide heat for only one room. Fire places, stoves and space heaters are some examples.
Explain central heating systems
They provide heat from a single source such as a furnace. The heat transfers through a series of ducts or pipes. And comes out through the vents
What is forces air heating?
Air is heated by burning fuel and is blowed by a fan through ducts but goes through a filter first
What is hot-water heating?
What is heated in a boiler then a pump forces the air through metal radiators that warms the air. As the water cools it is returned to the boiler
What direction does heat travel?
From an area of high kinetic energy to low kinetic energy
How does a freezer work?
The refrigerant in a fridge evaporates at a very low temperature and that creates the cool air.
What is an insulator?
It limits the amount of heat transferred by conduction.
Where does most heat loss occur in a home?
35% through walls
What are fossil fuels?
A natural fuel such a gas from remains of fossilized organisms
What are renewable resources?
Resources that can be replaced.
E.g such as the Suns energy
What are non renewable resources?
Resources that cannot be replaced
E.g such a oil
Where is oil & natural gas found?
They are usually extracted from the ground by pumping
