Science Chapter 10 - Transfer Of Heat Energy & Its Effects Flashcards
(24 cards)
What is temperature?
Temperature is a measure of how hot or cold an object is.
SI unit for temperature
Kelvin (K).
What does a change in temperature indicate?
A change in temperature indicates a transfer of thermal energy.
What is heat?
It refers to the amount of thermal energy that is being transferred from a hotter region to a colder region.
How does thermal energy flow?
Thermal energy always flows from a region of higher temperature to a region of lower temperature until 2 bodies are in thermal equilibrium.
What happens to the solid particles when they are heated?
When the solid particles are heated, the particles gain energy & vibrate faster, moving further apart & causing the distance between particles to increase, thus taking up more space & causing the volume to increase.
(Expansion) What happens to the particles?
The particles gain thermal energy (which will be converted to kinetic energy) and vibrate more vigorously.
(Expansion) Distance between the particles?
Increase.
(Expansion) Volume of matter?
Increase.
(Expansion) Density of matter?
Decrease.
(Contraction) What happens to the particles?
The particles lose thermal energy (which will be converted to kinetic energy) and vibrate less vigorously.
(Contraction) Distance between the particles?
Decrease.
(Expansion) Volume of matter?
Increase.
(Contraction) Density of matter?
Increase.
Will the mass, volume and density of the matter change?
The mass of the matter does not change while the volume and density of the matter will change.
Will the mass, volume and density of the particles change?
No, the mass, volume and density of the particles will not change.
Why is it that in general, solids expand & contract the least, gases expand and contract the most (liquids are somewhere in between)?
Generally, gases have the weakest forces of attraction between the particles, so the particles can move much further apart than in liquids & solids,
What is a bimetallic strip
It is made up of 2 metals that expand & contract at different rates upon the same change in temperature.
What happens when the bimetallic strip is heated?
When heated, brass expands more than steel, causing the bimetallic strip to bend downwards with brass on the outward side & steel on the inward side.
What happens when the bimetallic strip is cooled?
When cooled, brass contracts more than steel, causing the bimetallic strip to bend upwards with the brass on the inward side & steel on the outward side.
How is thermal energy transferred? (Which 3 processes?)
Conduction, convection and radiation.
What is conduction?
It is the transfer of thermal energy without the physical movement of the medium.
What is convection?
It is the transfer of thermal energy from one place to another by the physical movement of the medium due to a difference in density.
What is radiation
It is the transfer of thermal energy from a hotter body to a cooler body without the need for a medium.
