พลังงานความร้อน

Conduction can only occur between two objects when –

• one object is less dense than the other.
• both objects are in physical contact with each other.
• one of the objects is made of a metal.
• both objects are exactly the same temperature.

In the situation illustrated, how will heat energy move? Heat energy will be transferred from –

• the water to the hot plate by convection.
• the water to the hot plate by conduction.
• the hot plate to the water by convection.
• the hot plate to the water by conduction.

Radiation is a method of thermal energy transfer that moves -

• through empty space.
• when objects touch.
• only through solids.
• in the motion of fluids.

An example of a situation in which an egg is receiving thermal energy through convection -

• The egg is kept warm by its mother in the nest.
• An egg cracked on a hot sidewalk starts to cook.
• The egg is hard boiled in a pot of water.
• A metal pan on the stove fries the egg.

Which of the following describes a way in which heat energy will be transferred by conduction?

• Sample 1 to Sample 2
• Sample 3 to Sample 2
• Sample 3 to Sample 1
• Sample 2 to Sample 3

Which of the following sets of tools would be the MOST useful for measuring the transfer rate of thermal energy in four different liquids -

• Triple-beam balance, beakers, metric ruler
• Hot plate, beakers, thermometers
• Microscope, funnel, metric ruler
• pH meter, test tubes, forceps

Where would energy transfer by conduction move downward, from a higher block to a lower block?

• Sample 2 to Sample 4
• Sample 1 to Sample 2
• Sample 3 to Sample 4
• Sample 1 to Sample 3

Which was the most effective at preventing heat transfer from the water to the environment?

• Container P
• Container Q
• Container R
• Container S

What two kinds of heat transfer are represented?

• stove→pot=radiation pot→egg=conduction
• stove→pot=conduction pot→egg=radiation
• stove→pot=convection pot→egg=conduction
• stove→pot=conduction pot→egg=convection

What was the change in temperature resulting from this heat transfer in degrees Celsius?

• 4.5
• 6.0
• 5.5
• 7