20. Heat and Temperature

In the context of popping popcorn in a microwave, how does heat primarily transfer from the hot filament to the popcorn kernel?

When a beam of $\mathrm{thermal} \mathrm{radiation}$ strikes two different surfaces, one made of $\mathrm{ground}\left(\mathrm{soil}\right)$ and the other of $\mathrm{polished} \mathrm{marble}$, which surface will reflect more $\mathrm{thermal} \mathrm{energy}$?

Which of the following is considered the most direct type of heat transfer?

Which of the following lists correctly identifies the three primary mechanisms by which $\mathrm{heat}$ is transferred?

In the context of heat transfer, can frozen ice transfer thermal energy to another substance?

The blood plays an important role in removing heat from the body by bringing this energy directly to the surface where it can radiate away. Nevertheless, this heat must still travel through the skin before it can radiate away. Assume that the blood is brought to the bottom layer of skin at $37.0$°C and that the outer surface of the skin is at $30.0$°C. Skin varies in thickness from $0.50$ mm to a few millimeters on the palms and soles, so assume an average thickness of $0.75$ mm. A $165$-lb, $6$-ft-tall person has a surface area of about $2.0$ m² and loses heat at a net rate of $75$ W while resting. On the basis of our assumptions, what is the thermal conductivity of this person's skin?

Suppose that the rod in Fig. $17.24$a is made of copper, is $45.0$ cm long, and has a cross-sectional area of $1.25$ cm² . Let $TH=100.0$°C and $TC=0.0$°C. What is the final steady-state temperature gradient along the rod?

In the context of heat transfer, what is the name of the process by which heat is transferred through direct contact between two objects?

Which of the following best describes the primary mode of heat transfer responsible for the heat you can feel when you place your hand near the engine of a running car?

Which of the following scenarios is best categorized as heat transfer by conduction?

Which of the following best describes conduction in the context of heat transfer?

A mug of coffee cools down by $\frac{1}{2}$ degree Celsius in $\frac{1}{5}$ minute. What is the rate at which the coffee is cooling, in degrees Celsius per minute?

Which type of heat transfer primarily occurs in fluids such as liquids and gases?

Heat traveling through a pan to warm food in the pan is an example of what kind of heat transfer?