Self+Check+Questions

Q1. Explain how energy moves when you touch a block of ice with your hand. A1. Heat from your hand is transfered to the ice, so the particals move faster and melt.
 * __Section 1-__**

Q2. Describe how the thermal energy of an object changes when the object's temperature changes. A2. As the temperature changes the thermal energy changes. As kenetic energy changes thermal energy changes too.

Q3. Infer when heat flows between two objects changes when the object's temperature changes. A3. No, the temperature change depends on the heat of each material.

Q4. Explain why the specific heat of water is higher than the specific heat of most other substances. A4. The specific heat of water is highter than the specific heat of most other substances, because it retains more heat, because the chemical bods are stronger.

Q5. Think Critically. Expain whether or not the following statement is true: for any two objects, the one with the higher temperature always has more thermal energy. A5. False, it depends on the amount of material in the object and the potential energy of the particles in the object.

Q1: Explain why materials that are good conductors of heat are poor insulators. A1: Materials such as metals, that are good conductors of heat are poos insulators. Because in these materials, heat flows more rapidly from one place to another.
 * __Section 2-__**

Q2: Explain why the air temperature near the ceiling of a room tends to be warmer than near the floor. A2: Because heat rises.

Q3: Predict whether plastic foam, which contains pockets of air, would be a good conductor or a good insulator. A3: It would be a good insulator because, say if you were a runner and you were running it would help reduce the flow of the runner's body heat to the colder air outside.

Q4: Describe how a convection current occurs. A4: Convection currents transfer heat from warmer to cooler parts of the fluid. In a convection current, both conduction and convection transfer thermal energy.

Q5: Think critically, several days after a snowfall, the roofs of some homes on a street have almsot no snow on them, while the roofs of other houses are sill snowcovered. Descirbe what would cause this difference. A5: Shingles that are light-colored reflect more radiant energy, while dark-colored shingles absorb more radiant energy.

Q1: Explain how the thermal energy of a closed system changes with time. A1:
 * __Section 3:__**

Q2: Compare and contrast an active solor A2:

Q3:Explain whether or not a heat engine could be made 100 percent efficient by eliminating friction. A3:

Q4: Diagram how the thermal energy of the coolant changes as it flows in a refrigerator. A4:

Q5: Think Critically Suppose you vigorously shake a bottle of fruit juice. PRedict how the termperature of the juice will change. Explain your reasoning. A5: