ch22.ppt

Multiple Choice

When several objects with different temperatures are placed near each other, what eventually happens to their temperatures?

• They all reach a common temperature.

• The warm objects get warmer and the cool objects get cooler.

• Their temperatures remain unchanged.

• Only the coolest object changes temperature.

Multiple Choice

Which statement best describes the process of conduction as explained in the slides?

• Conduction involves the transfer of matter between objects.

• Conduction is the transfer of thermal energy through collisions between particles, without overall transfer of matter.

• Conduction only occurs in liquids.

• Conduction requires a chemical reaction between materials.

Open Ended

Explain how heat is transferred through an iron rod when one end is placed in a flame.

Multiple Select

Which of the following are characteristics of good conductors of heat?

• Composed of atoms with tightly bound outer electrons

• Composed of atoms with loose outer electrons

• Metals are generally good conductors

• Nonmetals are generally good conductors

Multiple Choice

Which of the following statements about heat transfer between your hand and a piece of wood or metal is correct?

• Heat moves easily from your hand into both wood and metal.

• Metal feels colder because it is a poor conductor.

• Wood feels colder because it is a better conductor.

• Heat moves easily from your hand into metal, but not into wood.

Open Ended

Why does metal feel colder than wood when both are at room temperature?

Multiple Choice

Why does a tile floor feel colder to bare feet than a carpet at the same temperature?

• Tile is a better conductor than carpet

• Tile is a better insulator than carpet

• Carpet is colder than tile

• Carpet absorbs more heat than tile

Multiple Select

Which of the following materials are considered good insulators?

• Air

• Wool

• Tile

• Polystyrene

Open Ended

Explain how air spaces in materials contribute to their insulating properties. Use examples from the slides.

Multiple Choice

What is the main purpose of insulation in homes according to the slides?

• To keep cold out

• To keep heat in

• To prevent air flow

• To increase temperature

Multiple Choice

Why does snow last longer on the roof of a well-insulated house?

• Because insulation slows down heat transfer from the house to the roof

• Because snow is a source of heat

• Because the roof is colder than the air

• Because insulation increases the temperature of the roof

Open Ended

If you hold one end of a metal bar against a piece of ice, the end in your hand will soon become cold. Does cold flow from the ice to your hand?

Multiple Choice

Which of the following best explains why metal feels colder than wood at the same temperature?

• Metal is a better conductor of heat than wood.

• Metal is always colder than wood.

• Wood absorbs more heat than metal.

• Wood is a better conductor of heat than metal.

Open Ended

You can place your hand into a hot pizza oven for several seconds without harm, whereas you’d never touch the metal inside surfaces for even a second. Why?

Open Ended

How does conduction transfer heat?

Multiple Select

Which of the following statements about conduction and convection is/are correct?

• Conduction transfers heat through direct contact of particles.

• Convection involves movement of the substance itself.

• Both conduction and convection require a medium to transfer heat.

• Conduction can occur in a vacuum.

Multiple Choice

Which of the following best describes convection as a means of heat transfer?

• Movement of heated substance itself, such as by currents in a fluid

• Transfer of heat through direct contact between objects

• Transfer of heat by electromagnetic waves

• Transfer of heat through vacuum

Open Ended

Explain how convection currents are formed in fluids and describe their effect on the distribution of heat.

Multiple Select

Which of the following are examples of convection currents transferring heat?

• Air rising above a hot stove

• Water circulating in a boiling pot

• Metal rod heating up from one end

• Sunlight warming the Earth's surface

Open Ended

Describe what happens when the top of a test tube filled with water and ice at the bottom is heated, and explain the role of conduction and convection in this scenario.

Multiple Choice

Why does the ice at the bottom of the test tube remain unmelted when the top is heated?

• Water is a poor conductor and convection is prevented

• The ice is protected by steel wool

• The flame is not hot enough to melt the ice

• The test tube is too thick

Open Ended

Reflecting on today's lesson about heat transfer, what is one real-life example where you have observed heat moving from a warmer object to a cooler one?