Q: A steel rod of length $$L_0 = 2.0$$\ \text{m}$$ at 20$$^\circ\text{C}$$ is heated to 100$$^\circ\text{C}$$. If the coefficient of linear expansion for steel is $$\alpha = 1.2 \times $$10^{-5}$$\ \text{K}^{-1}$$, what is the change in length $$\Delta L$$?

$$\Delta L = \alpha L_0$ \Delta T = 1.92 \times 10$$^{-3}$$\ \text{m}$$

Q: A 50.0 m steel measuring tape is calibrated at $$20^\circ\text{C}. $$What is its length at $$35^\circ\text{C} if$$ $$\alpha = 1.2 \times 10$$^{-5}$$\ \text{K}^{-1}$$?

$$L = 50.0\ \text{m} + (1.2 \times 10$$^{-5}$$)(50.0)(15) = 50.009\ \text{m}$$

Q: A 100 g block of ice at $$0^\circ\text{C} is $$melted by adding heat. If the latent heat of fusion for ice is $$L_f = 334\ \text{J/g}$$, how much heat is required?

$$Q = mL_f = 33,400\ \text{J}$$

Question 1

Which statement best describes the Zeroth Law of Thermodynamics?

Accepted Answer

If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other.

Question 2

A steel rod of length $$L_0 = 2.0$$\ 	ext{m}$$ at 20$$^\circ	ext{C}$$ is heated to 100$$^\circ	ext{C}$$. If the coefficient of linear expansion for steel is $$\alpha = 1.2 	imes $$10^{-5}$$\ 	ext{K}^{-1}$$, what is the change in length $$\Delta L$$?

Accepted Answer

$$\Delta L = \alpha L_0$ \Delta T = 1.92 	imes 10$$^{-3}$$\ 	ext{m}$$

Question 3

Which of the following is true about the Kelvin temperature scale?

Accepted Answer

Kelvin temperatures are measured in kelvins, not degrees kelvin.

Question 4

A 50.0 m steel measuring tape is calibrated at $$20^\circ	ext{C}. $$What is its length at $$35^\circ	ext{C} if$$ $$\alpha = 1.2 	imes 10$$^{-5}$$\ 	ext{K}^{-1}$$?

Accepted Answer

$$L = 50.0\ 	ext{m} + (1.2 	imes 10$$^{-5}$$)(50.0)(15) = 50.009\ 	ext{m}$$

Question 5

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

Accepted Answer

Radiation

Question 6

A 100 g block of ice at $$0^\circ	ext{C} is $$melted by adding heat. If the latent heat of fusion for ice is $$L_f = 334\ 	ext{J/g}$$, how much heat is required?

Accepted Answer

$$Q = mL_f = 33,400\ 	ext{J}$$

Question 7

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

Accepted Answer

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

Question 8

During a phase change, such as melting or boiling, what happens to the temperature of the substance?

Accepted Answer

The temperature remains constant during the phase change.

Question 9

A bridge is constructed with expansion joints. What is the primary reason for including these joints?

Accepted Answer

To accommodate changes in length due to thermal expansion and prevent structural damage.

Question 10

Which formula gives the heat required to change the temperature of a mass $$m of $$material by $$\Delta T$$?

Accepted Answer

$$Q = mc\Delta T$$

Question 11

Water exhibits anomalous expansion between $$0^\circ	ext{C}$$ and $$4^\circ	ext{C}. $$What is the consequence of this behavior in nature?

Accepted Answer

Lakes freeze from the top down, not from the bottom up.

Question 12

A metal plate with a hole is heated. What happens to the hole?

Accepted Answer

The hole expands as the plate expands.

Question 13

Which equation describes the heat required to change the temperature of $$n$$ moles of a material by $$\Delta T$$?

Accepted Answer

$$Q = nC\Delta T$$

Question 14

A person steps out of a swimming pool and feels cold. Which physical process is responsible for this sensation?

Accepted Answer

Evaporation removes heat from the body due to the heat of vaporization.

Question 15

Which equation describes the heat transfer during a phase change?

Accepted Answer

$$Q = mL$$

Question 16

Which equation describes the rate of heat transfer by radiation from a surface?

Accepted Answer

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

Question 17

A rod is prevented from expanding as its temperature increases. What develops in the rod?

Accepted Answer

Thermal stress

Question 18

Which of the following is NOT a mechanism of heat transfer?

Accepted Answer

Reflection

Question 19

A 0.5 kg sample of water is heated from $$20^\circ	ext{C} to$$ $$80^\circ	ext{C}. If $$the specific heat of water is $$c = 4186\ 	ext{J/kg}\cdot	ext{K}$$, how much heat is required?

Accepted Answer

$$Q = mc\Delta T = 0.5 	imes 4186 	imes 60 = 125,580\ 	ext{J}$$

Chapter 17: Temperature and Heat – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard