Physics Flashcards
Define energy:
The work that a certain force can do.
What is energy measured in ?
Joule or Joules
What is thermal energy?
heat;the kinetic energy of particles that increase as their temperature increases.
What is a conductor and give an example?
A conductor is any material that allows thermal energy to flow easily through it.
Eg: Metal, dry wood
What is an insulator and give an example?
A substance that slows down the movement of thermal or electrical energy.
Eg: Wool, Dry air
What is a temperature gradient?
The difference in temperatures between two systems, such as an ice block and warm air.
Define thermal equilibrium:
When two systems are at the same temperature; no heat moves from one system to another.
What is absolute zero?
-273°C
What is the difference between conduction and convection?
Conduction is the transfer of thermal energy through direct contact, convection molecules move from one place to another.
What are some forms of electromagnetic radiation?
Ultraviolet rays and light, x-rays, gamma rays, radio waves and infrared rays.
Source of radiant thermal energy be absorbed into an object.
Radiation is not the necessarily absorbed when it meets a substance- it maybe reflected or transmitted.
How does Earth maintain a habitable temperature?
Radiation; the suns energy travels millions of kilometres to reach Earth, then it passes through the Earth’s atmosphere heating the air.
What is radiation?
The transfer of thermal energy (via photons) across a empty space or through another substance.
What is conduction?
The transfer of thermal energy through direct contact; the atoms do not change their position in the material.
What is convection?
The transfer of thermal energy by the movement of molecules in air or liquid from one place to another.
