Thermal Energy Unit Test
8 of 108 of 10 Items
Question
A teacher opens a window on a cold day. Which statement explains why the room starts to feel cooler? (1 point)
Responses
Air moves from the areas of higher temperature to areas of lower temperature.
Air moves from the areas of higher temperature to areas of lower temperature.
Cold air is moving into the room from outside.
Cold air is moving into the room from outside.
The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside.
The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside.
The density of the air is lower on the inside than on the outside.
The correct answer is: Cold air is moving into the room from outside.
A student takes the temperature of a bottle of liquid water and a tub filled with ice. The student then places the bottle of liquid water into the tub of ice. After 15 minutes, which of the follow best describes what happens to the temperature of each?
(1 point)
Responses
Both the bottle and the ice stay the same temperature
Both the bottle and the ice stay the same temperature
The temperature of both the ice and water decrease.
The temperature of both the ice and water decrease.
The temperature of the ice increases, while the temperature of the water decreases
The temperature of the ice increases, while the temperature of the water decreases
The temperature of the ice decreases, while the temperature of the water increases
The correct answer is: The temperature of the ice decreases, while the temperature of the water increases.
To determine the correct statement explaining why the room starts to feel cooler when a teacher opens a window on a cold day, let's analyze each option:
1. Air moves from the areas of higher temperature to areas of lower temperature: This is a general principle of heat transfer. When there is a temperature difference between two areas, heat (or in this case, thermal energy) will naturally flow from the higher temperature area to the lower temperature area. As a result, the room will start to feel cooler.
2. Cold air is moving into the room from outside: While it is true that cold air from outside enters the room through the open window, this statement alone doesn't fully explain why the room starts to feel cooler. It is the movement of air driven by temperature differences that causes the cooling effect.
3. The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside: Kinetic energy is related to the motion of molecules. In general, higher kinetic energy means higher molecular motion, which corresponds to higher temperature. Thus, if the air molecules outside have higher kinetic energy, it implies that they are at a higher temperature than the air molecules inside the room. As mentioned earlier, heat will flow from areas of higher temperature to areas of lower temperature, resulting in the room feeling cooler.
4. The density of the air is lower on the inside than on the outside: Density refers to the mass of air per unit volume. While a difference in density could affect how air moves, it does not fully explain why the room feels cooler. The movement of air due to temperature differences is the primary cause of the cooling effect, not solely differences in air density.
Based on the explanations above, the correct statement that explains why the room starts to feel cooler when a teacher opens a window on a cold day is:
- The kinetic energy of the air molecules outside is higher than the kinetic energy of the air molecules inside.
This statement captures the principle of heat transfer and the movement of air from higher temperature areas to lower temperature areas.