Question 1

Which of the following statements best describes thermal equilibrium?

Accepted Answer

Two objects are in thermal equilibrium if they have the same temperature.

Question 2

According to the Zeroth Law of Thermodynamics, if system A is in thermal equilibrium with system C, and system B is also in thermal equilibrium with system C, what can be concluded?

Accepted Answer

System A and B are in thermal equilibrium with each other.

Question 3

Which equation correctly relates the Celsius and Kelvin temperature scales?

Accepted Answer

$$T_{K} = T_{C} + 273.15$$

Question 4

A steel bridge is 100 m long at $$0^{\circ}C$. If the coefficient of linear expansion for steel is 1.2$$ 	imes $$10^{-5}$$ $$/ ^{\circ}C$, what is the change in length when the temperature increases to 40$$^{\circ}$$C$$?

Accepted Answer

$$\Delta L = 0.048\,	ext{m}$$

Question 5

Which of the following best explains why lakes freeze from the top down rather than the bottom up?

Accepted Answer

Water has its maximum density at $$4^{\circ}C$.

Question 6

A 0.5 kg block of aluminum ($$c = 900\,	ext{J/kg} \$$cdot ^{\circ}$$C) is $$heated from $$20^{\circ}C$ to 50$$^{\circ}$$C. $$How much heat is required?

Accepted Answer

$$Q = 13,500\,	ext{J}$$

Question 7

Which equation gives the amount of heat required to change the temperature of a mass $$m of a $$substance by $$\Delta T$$?

Accepted Answer

$$Q = mc\Delta T$$

Question 8

During a phase change from solid to liquid, which of the following is true?

Accepted Answer

The temperature of the substance remains constant.

Question 9

A 100 g sample of ice at $$0^{\circ}C$ is placed in 200 g of water at 30$$^{\circ}$$C. $$What is the final temperature of the mixture? (Assume no heat loss to the environment, $$c_{water} = 4186\,	ext{J/kg} \$$cdot ^{\circ}$$C$$, $$L_f = 334,000\,	ext{J/kg})$$

Accepted Answer

The final temperature is between $$0^{\circ}C$ and 30$$^{\circ}$$C$$ with all ice melted.

Question 10

Which of the following equations describes the rate of heat transfer by conduction through a rod?

Accepted Answer

$$\frac{dQ}{dt} = \frac{kA(T_H - T_C)}{L}$$

Question 11

A metal plate with a circular hole is uniformly heated. What happens to the diameter of the hole?

Accepted Answer

The diameter increases.

Question 12

Which mechanism of heat transfer does NOT require matter to be present between two objects?

Accepted Answer

Radiation

Question 13

A blackbody emits thermal radiation according to the Stefan-Boltzmann law. Which equation gives the power radiated?

Accepted Answer

$$H = \sigma A e T^4$

Question 14

A steel rod is fixed at both ends and its temperature increases. What is the resulting effect?

Accepted Answer

Thermal stress develops in the rod.

Question 15

Which of the following best describes the physical meaning of specific heat?

Accepted Answer

The amount of heat required to raise the temperature of 1 kg of a substance by $$1^{\circ}C$.

Question 16

A 2 kg block of copper ($$c = 386\,	ext{J/kg} \$$cdot ^{\circ}$$C) at$$ $$100^{\circ}C$ is placed in 5 kg of water at 20$$^{\circ}$$C. $$What is the final equilibrium temperature? (Neglect heat loss to the environment.)

Accepted Answer

The final temperature is between $$20^{\circ}C$ and 100$$^{\circ}$$C.$$

Question 17

Which of the following is a real-world application of thermal expansion?

Accepted Answer

Gaps in railroad tracks to prevent buckling.

Question 18

Which property of water is responsible for the fact that aquatic life can survive in lakes during winter?

Accepted Answer

Water is most dense at $$4^{\circ}C$.

Question 19

Which of the following best describes convection?

Accepted Answer

Heat transfer by the bulk movement of fluid.

Chapter 17: Temperature and Heat – Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard