Physics, heating,cooling and sound Flashcards
What is the definition of temperature?
A measure of energy of individual particles measured in degrees Celsius
What is the definition of thermal energy?
A measure of the total amount of energy in an object measures in joules
What is thermal conducter?
Material that allows heat to move quickly through it.
What is the definition of thermal insulator?
Material that only allows heat to travel slowly through it
What is conduction?
Transfer of thermal energy through solids by the vibration of particles
What is convection?
Transfer of thermal energy through fluids (liquid and gases) when hot fluid rises
What is radiation?
Transfer of thermal energy as a wave. It does not require partials so can occur through a vacuum
Conductor
A substance that transfers energy easily from the hot part to the cold part is a conductor. Metals are good conductors
What are insulators?
A substance that does not easily transfer energy from a hot part to a cold part. Air and plastic are good insulators.
How does double glazing windows help with insulation?
The two panes of glass have air in between them which reduces conduction.
How can energy loss through walls be reduced?
Using cavity wall insulation and rapped air.
How do partials work during conduction?
When a substance is heated it’s partials gain internal energy bumping into nearby partials making them vibrate
What happens to the particles during convection?
The partials in liquid and gases can move. When heated they move more vigorously and become more spaced out. Makes the fluid less dense so it rises. Cooler fluid replaced the hotter fluid and the process continues.
How do all objects transfer their surroundings by?
Infrared radiation
Are partials involved in radiation?
No particals are involved unlike conduction this means that energy transfer can happen without objects touching even in space.
What is a wave?
A method of transferring energy via vibrations without transferring matter
What is a transverse wave?
Has vibrations that are perpendicular to the direction of the wave energy transfer. It has crests on top of the wave and troughs on the bottom
What is longitudinal wave
Vibrations that are parallel to the direction of the wave energy transfer. It has compressions (particals close together) and rarefractions (particals) spread out.
What is an electromagnet?
It does not require particals to travel, it can travel in a vacuum
What is a mechanical wave?
Requires particals to travel. It cannot travel in a vacuum
What is a vaccum
An area with no particals such as space
What is the wavelength?
The distance between two consecutive same points Ona are eg: from a crest to the next.
What is the amplitude?
Distance from the rest position of the wave to its maximum height at a crest
What is the frequency?
The number of waves passing a point per second
What does the frequency do?
It affects the pitch the higher the frequency, the higher the pitch
What does the amplitude do?
The amplitude of a sound wave affects the volume the higher the amplitude the higher the volume.
What is the speed of sound in air?
340 m/s
What is the equation for the speed of sound?
Speed = distance/ time
What is the human range of hearing ?
20Hz to 20,000Hz sound waves above this are known as ultrasound
