Question 1

Your refrigerator is in your kitchen. If you try to cool your kitchen on a hot day by operating your refrigerator with its door open, the kitchen temperature will

Accepted Answer

Operating a refrigerator with its door open will actually increase the kitchen temperature. This is because refrigerators remove heat from their interior and release it into the surrounding environment. With the door open, the refrigerator works harder to cool the inside, which is now effectively the entire kitchen, leading to more heat being expelled into the room than if the refrigerator were closed.

Question 2

When you touch a cold piece of ice with your finger, energy flows

Accepted Answer

Energy flows from your finger to the ice because heat transfer always occurs from a warmer object to a cooler one, causing the ice to absorb heat and potentially melt.

Question 3

Consider a sample of ice at 0 degrees C. If the temperature is decreased, the volume of the ice

Accepted Answer

When the temperature of ice is decreased below 0 degrees Celsius, its volume decreases because the ice contracts as it gets colder, becoming denser until it reaches a certain point around -200 degrees Celsius.

Question 4

Consider a steaming aluminum soda-pop can that contains a small amount of boiling water. When it is quickly inverted into a bath of cooler water the can is dramatically crushed by atmospheric pressure. This occurs because the pressure inside the can is rapidly reduced by

Accepted Answer

The rapid condensation of steam inside the can significantly reduces the internal pressure. When the can is inverted into cooler water, the steam condenses into water, leaving much less gas inside to exert pressure against the atmospheric pressure outside, leading to the can's collapse.

Question 5

When we enlarge a photograph of an iron ring, the image of the hole becomes

Accepted Answer

When a photograph of an iron ring is enlarged, the entire image, including the image of the hole, becomes larger. This is because enlargement increases the dimensions of all parts of the image proportionally.

Question 6

As a system becomes more disordered, entropy

Accepted Answer

Entropy is a measure of the disorder or randomness in a system, so as a system becomes more disordered, its entropy increases.

Question 7

Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This
Would violate the

Accepted Answer

The second law of thermodynamics states that heat flows from a hotter object to a cooler one, aiming for thermal equilibrium. In this scenario, heat flowing in a manner that makes the cooler block even cooler and the warmer block warmer contradicts this principle, thus violating the second law of thermodynamics.

Question 8

To totally convert a given amount of mechanical energy into heat is

Accepted Answer

Mechanical energy can be entirely converted into heat through processes like friction, where kinetic energy is transformed into thermal energy.

Question 9

Heat energy travels from an object with a high

Accepted Answer

Heat energy always flows from a warmer object to a cooler object, which means it travels from an object with a higher temperature (a measure of its internal energy) to an object with a lower temperature. Therefore, choice B is the correct answer.

Question 10

Pour a liter of water at 40 degrees C into a liter of water at 20 degrees C and the final temperature of the two becomes

Accepted Answer

When you mix equal volumes of water at different temperatures, the final temperature is the average of the two initial temperatures, assuming no heat is lost to the surroundings. Here, (40°C + 20°C) / 2 = 30°C.

Question 11

The lowest temperature possible in nature is

Accepted Answer

-273 degrees C is equivalent to 0 Kelvin, which is the absolute zero temperature. At this temperature, particles have minimal thermal motion, making it the lowest temperature possible in nature.

Question 12

When ice floats in water, a small part of it extends above the surface. Interestingly enough, the volume of ice that extends above the surface is equal to the volume of the

Accepted Answer

The volume of ice that extends above the surface is due to the open spaces in the hexagonal structure of ice crystals, which makes ice less dense than water.

Question 13

If the specific heat of water were lower than it is, ponds in the cold of winter would be

Accepted Answer

If the specific heat of water were lower, it would require less energy to change its temperature, making it easier for ponds to lose heat and freeze in cold weather.

Question 14

Before ice can form on a lake, all the water in the lake must be cooled to

Accepted Answer

The answer of Before ice can form on a lake,...

Question 15

As a piece of metal with a hole in it cools, the diameter of the hole

Accepted Answer

As the metal cools, it contracts, reducing its overall size. This reduction in size affects the hole as well, causing it to also contract, thus decreasing its diameter.

Question 16

A volume of air has a temperature of 0 degrees Celsius. An equal volume of air that is twice as hot has a temperature of

Accepted Answer

The temperature of air is directly proportional to its absolute temperature. Absolute temperature is measured in Kelvin, and 0 degrees Celsius is equal to 273 Kelvin. Therefore, an equal volume of air that is twice as hot has a temperature of 2 * 273 = 546 Kelvin, which is equal to 273 degrees Celsius.

Question 17

Between 0 degrees Celsius and 8 degrees Celsius a red-dyed-water-in-glass thermometer would

Accepted Answer

The answer of Between 0 degrees Celsius and 8 degrees...

Question 18

Which of the following contracts most when the temperature is decreased? Equal volumes of

Accepted Answer

Helium, being a gas, will contract more than solids or liquids when the temperature is decreased due to the significant decrease in the kinetic energy of its particles, leading to a reduction in volume according to the ideal gas law (PV=nRT).

Question 19

To wholly convert a given amount of heat energy into mechanical energy is

Accepted Answer

This is because of the Second Law of Thermodynamics, which states that it is impossible to convert all the heat energy into mechanical energy without any losses in the form of waste heat.

Question 20

Suppose the temperature of the input reservoir in a heat engine doesn't change. As the sink temperature is lowered, the efficiency of the engine

Accepted Answer

The efficiency of a heat engine is given by $1 - \frac{T_{\text{cold}}}{T_{\text{hot}}}$, where $T_{\text{cold}}$ is the temperature of the cold reservoir (sink) and $T_{\text{hot}}$ is the temperature of the hot reservoir (source). If $T_{\text{hot}}$ remains constant and $T_{\text{cold}}$ is lowered, the fraction $\frac{T_{\text{cold}}}{T_{\text{hot}}}$ decreases, leading to an increase in efficiency.

Quiz 8: Temperature, Heat, and Thermodynamics