Heat Chapter40 Flashcards
What is the unit of heat?
Joules
Name 2 ways in which heat can be changed into other forms of energy?
Heat can be changed to light and sound energy.
What forms of energy can be changed to heat?
Kinetic (when you rub your hands together).
Chemical (burning coal).
What happens when a solid or liquid is heated
Solid expands
Liquid evaporates
Name 3 disadvantages of solid expanding when heated?
Railway tracks need tapered joints to allow expansion.
What is the definition of heat?
It is a form of energy.
When is expansion good/bad
Good- thermometers, bimetallic strips, engines.
Bad- bridges and railway tracks.
What experiment shows that solids, liquids and gases expand when heated?
Solid- ring and ball.
Liquid- round bottom flask.
Gas- hair dyer and bubbles
Why is water a exception to the contraction when cooled rule?
Because at 4*c it starts the freeze and the ice bulks.
What is the difference between heat and temperature?
Heat is a form of energy measures in joules. Temperature is the amount of heat in something and measured in degrees Celsius.
What is the definition of radiation
The transfer of heat from a warm substance to a cold without needing a medium.
