Transfer of Thermal Energy
Explain how energy from the sun travels to Earth and warms it.
Radiation is the transfer of thermal energy by waves that travels through empty space. The earth is warmed by the energy that radiates from the sun. This causes the earth to warm up.
Thermal energy is always transferred from cooler to warmer objects.
False
A material that is good at conducting thermal energy is referred to as a ____________________________.
thermal conductor
Conduction occurs when particles of matter flow.
False
_______________ is the transfer of thermal energy between particles of matter that are touching.
Conduction
Compare and contrast conduction and convection.
Conduction is the transfer of thermal energy through particles of matter that are touching. Materials that can transfer thermal energy quickly and easily are good thermal conductors. Convection is the transfer of thermal energy by particles moving through a fluid. Convection works only in liquids and gases (fluids) because their particles can move apart from each other and flow. They both transfer thermal energy, but by different ways.
Only hot objects radiate thermal energy.
False
Insulation can keep a house cool on a hot day.
True
Land and sea breezes are examples of convection currents.
True
In which substance can thermal energy be transferred by convection? a. air b. sand c. wood d. two of the above
a. air
Thermal energy is transferred through the ocean by: a. currents. b. waves. c. winds. d. tides.
a. currents.
Conduction is usually slowest in: a. gases. b. solids. c. liquids. d. flames.
a. gases.
Which of the following materials is a thermal insulator? a. plastic b. iron c. copper d. steel
a. plastic
Matter is not needed for the transfer of thermal energy by: a. conduction. b. convection. c. radiation. d. two of the above
c. radiation.
The transfer of thermal energy by particles moving through a fluid is known as _____________.
convection
The flow of particles in a fluid due to differences in temperature and density is called a(n) ________________________________.
convection current
The transfer of thermal energy by waves that can travel through space is called ___________.
radiation