heat and temperature (4-6) Flashcards
what is an energy source ?
An energy source is an object or material that can transfer its energy to other objects.
. Three types of energy transfer:
radiation, covection, and conduction
does energy take up space?
NO!! It is not matter, it does not take up space. It has the ability to make something happen. Light, heat, sound, motion, and electricity are all forms of energy.
what is radiation?
The transfer of energy without any movement of matter. Example; microwave, sun, x-rays
how is energy transferred?
Energy is transferred by radianat energy or electromagnetic radiation (EMR).
what is emr?
electromagnetic radiation
how does EMR travel?
t travels like a wave and it travels through empty space, air, glass and many other materials.
what are 5 forms or EMR?
- Radio waves (cell phone tower waves)
- Microwaves
- Visible light
- X - rays
- Infrared radiation
what are the charectoristics that all diffrent forms or radiant energy share?
they behave like waves, they can be absorbed and reflected by objects and can travel across empty space at speeds up to 300 000 km/s
what is conduction?
It is a form of energy transfer through direct collision of particles. Example: a pot on a stove
Use the particle theory to explain how thermal conduction works when you place a metal spoon into a bowl of HOT soup.
The high energy particles from the soup collided with the particles from the spoon. The particles from the spoon gained energy, began moving faster colliding with other particles in the spoon….thus the spoon felt hot.
why are poor conductors good heat insulators?
When they are wrapped around an object, they slow down the transfer of thermal energy to or from the surroundings.
what is convection?
A process by which a warm fluid (liquid or a gas) moves from place-to-place carrying thermal energy.
explain what happens in convection
a hot fluid can force its way through a colder fluid. in convection the warmer fluid moves from place to place carrying thermal energy
Using the particle theory, explain how convection currents work.
As particles warm up (gain energy), they move farther apart. Each section of the warmed material is left with fewer particles than when it was cold, so each section is a bit lighter. In other words, the material becomes less dense. These parts of the material rise. As the particles cool off, they become closer together and more dense. They sink, and the process starts all over.
