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