Heat Transfer

The diagram shows an example of convection. Which label belongs on the arrow? Warmer water sinks Warmer water rises Cooler water sinks Cooler water rises

Cooler water sinks

Alex studied the image shown. He concluded that the image shows thermal energy being transferred from the flames to the person's hands through conduction. Which best explains Alex's error? Thermal energy is being transferred from the person's hands to the flames. The image does not show thermal energy being transferred because the molecules of two substances or objects are not in direct contact. The image does not show conduction because the molecules of two substances or objects are not in direct contact. Thermal energy is being transferred from the surrounding air to the flames.

NOT Thermal energy is being transferred from the person's hands to the flames.

The diagram shows the movement of air as a result of convection currents. At which point is the air at its highest density? W X Y Z

NOT W

Which is an example of radiation? An ice pack is placed on a knee, and the knee cools down. A rock is warmed by an ultraviolet heat lamp. Hot coffee in a mug causes the mug to warm up. Cold salt water sinks to the bottom of the ocean.

NOT Hot coffee in a mug causes the mug to warm up.

Selma made a diagram to compare convection and radiation. Which label belongs in the area marked X? Must involve temperature differences between substances or objects Only occurs when molecules are in direct contact Involves the movement of fluids based on density differences Can occur where there is little or no matter

NOT Must involve temperature differences between substances or objects

Dante pours hot tea into a mug that is cool to the touch. Which best explains what will happen now? The tea will get warmer because the mug acts as a thermal insulator. The tea will get cooler because it gains energy from the mug. The mug will get warmer because thermal energy transfers from the tea to the mug. The mug will get warmer because the tea creates more thermal energy inside the mug.

NOT The mug will get warmer because the tea creates more thermal energy inside the mug.

Which condition must exist in order for conduction to occur between two substances? The molecules of the substances must be touching. Both substances must be the same temperature. At least one substance must be a liquid. Most of the molecules must be slow moving.

The molecules of the substances must be touching.

The law of conservation of energy states that energy cannot be or destroyed.

created

Thermal energy from the Sun travels to Earth by conduction. charged molecules. electromagnetic waves. convection currents.

electromagnetic waves.

Convection occurs when thermal energy is transferred by the movement of

fluids

The diagram shows the movement of magma due to convection currents. Based on the diagram, which part of Earth is the coolest? the crust the mantle the outer core the inner core

the crust

Which two conditions must exist in order for radiation to occur? the presence of a solid, liquid, or gas and a temperature difference direct contact of molecules and the presence of a solid, liquid, or gas the presence of electromagnetic waves and direct contact of molecules a temperature difference and the presence of electromagnetic waves

the presence of electromagnetic waves and direct contact of molecules

Which is an example of convection? In a mountain forest, the sun heats up the ground. On a hot day, Amaya pours water on her face to cool off. At the beach, Stephan's feet get hot walking across the sand. Above the sea, warm air rises, cools, and sinks.

Above the sea, warm air rises, cools, and sinks.

What are three properties of electromagnetic waves? They travel slower than the speed of light, they include visible light waves, and they can transfer energy through empty space. They need matter through which to travel, they travel at the speed of light, and they include visible light waves. They travel at the speed of light, they include ultraviolet waves, and they can transfer energy through empty space. They include ultraviolet waves, they need matter through which to travel, and they travel slower than the speed of light.

They travel at the speed of light, they include ultraviolet waves, and they can transfer energy through empty space.

Which best describes a wave? a collision of particles a disturbance that carries energy a movement of fluids a group of electrically charged molecules

a disturbance that carries energy