Yr 8 Physics Flashcards
Identify the type of heat transfer:
A room becomes warm after the heater is turned on
Convection
How does radiation transfer heat energy?
Heat Waves, spreads outwards to transfer heat
Energy flow diagram for releasing a bow and arrow
Elastic potential energy -> kinetic energy -> kinetic energy and gravitational potential energy
What state of matter does convection occur in?
Liquids and gases
Why can’t you hear heels on carpet?
The sound energy from both the objects cancel each other out. The carpet also absorbs the sound energy.
What’s the formula for Gravitational potential energy
GPE= m x g x h
(mass by gravity by height)
Convert g to kg
divide by 100
Identify the type of heat transfer:
A kettle is turned on and the water is boiled
Convection
How do you find kinetic energy?
GPE of point A - GPE of point B
Define conduction
Conduction happens when two objects are in contact with each other, or when a heat source is in direct contact with a material
Sound energy is a form of what kind of energy?
Kinetic energy
What is sound transmission?
the spread of sounds through materials and air
Convert j to jk
divide by 1000
List some examples of things or objects that use echo-location.
Energy flow diagram for a light bulb turning on
Chemical potential energy -> Electrical energy -> Light and heat energy
What state of matter does conduction happen in?
Solids
Define Insulation
Insulation isa material that resists or blocks the flow of heat energy (opposite of conduction/convection)
Contrast heat and sound energy
A saucepan on a stovetop is filled with water. Once left for a while, the water begins to boil.
a. Identify the types of heat transfer involved in this situation.
b. Explain why the water is able to heat up and boil.
a. Both conduction and convection
b. Conduction is heating the pot which is then heating the water inside causing it to boil
How does sound energy travel?
sound waves
What is the Law of Conservation of Energy?
Energy cannot be created or destroyed
What’s the formula for energy efficacy?
used energy/total energy x 100
