Question

heat transfer: conduction, convection, and radiation (worksheet)
q.1. fill in the blanks with suitable words.
a) ____________ is energy that is transferred of from warmer things to cooler things.
b) ____________ is the transfer of heat energy by direct contact.
c) ____________ is the transfer of heat energy by the movement of a gas or liquid.
d) ____________ is the transfer of heat energy by electromagnetic waves through air without direct contact.
q.2. label the three ways that heat can be transferred in the picture below.

• conduction • radiation • convection

q.3. how does the heat energy from the sun reach the earth?
a) conduction b) radiation c) convection d) expansion
q.4. write the type of heat transfer that takes place in the following images.
hot water rises, cold water sinks
a camp fire
microwave oven
holding mug feel hot
egg cooking in a hot pan
heated air rises, cools, then falls

Explanation:

a) Heat is the energy transferred from warmer to cooler things. Conduction is heat - transfer by direct contact. Convection is heat - transfer by the movement of a gas or liquid. Radiation is heat - transfer by electromagnetic waves without direct contact. For the Sun's heat reaching Earth, it's radiation as there is no direct contact medium between them. In the images: hot water rising and cold water sinking is convection; a camp - fire gives off heat by radiation; a microwave oven uses radiation; holding a hot mug is conduction; an egg cooking in a hot pan is conduction; heated air rising and then falling is convection.

Answer:

Q1:
a) Heat
b) Conduction
c) Convection
d) Radiation
Q2: (from left to right in the picture) Conduction (heat transfer through the pan handle), Radiation (heat waves coming out of the pan), Convection (circular motion of the liquid inside the pan)
Q3: b) Radiation
Q4:

• hot water rises, cold water sinks: Convection
• A camp fire: Radiation
• Microwave oven: Radiation
• Holding mug feel hot: Conduction
• Egg cooking in a hot pan: Conduction
• Heated air rises, cools, then falls: Convection