20. Heat and Temperature

The tungsten filaments inside of most incandescent lightbulbs reach temperatures of about 4580°F when the lightbulbs are lit. What is this temperature in a) Celsius and b) Kelvin?

(II) Typical temperatures in the interior of the Earth and Sun are about 4000°C and 15 x 10⁶ °C, respectively.

(b) What percent error is made in each case if a person forgets to change °C to K?

(I) (b) The temperature of the filament in a lightbulb is about 1900°C. What is this on the Fahrenheit scale?

(II) In an alcohol-in-glass thermometer, the alcohol column has length 12.61 cm at 0.0°C and length 22.79 cm at 100.0°C. What is the temperature if the column has length

(a) 18.50 cm, and

(II) A scuba tank is filled with air to a gauge pressure of 202 atm when the air temperature is 29°C. A diver then jumps into the ocean and, after a short time on the ocean surface, checks the tank’s pressure and finds that it is only 191 atm. Assuming the diver has inhaled a negligible amount of air from the tank, what is the temperature of the ocean water?

(II) A sealed metal container contains a gas at 30.0°C and absolute pressure 1.00 atm. To what temperature must the gas be heated for the pressure to double to 2.00 atm? (Ignore expansion of the container.)

(I) What are the following temperatures on the Kelvin scale:

(c) - 55° C?

(II) You buy an “airtight” potato chip bag packaged at sea level, and take the chips on an airplane flight. When you take the potato chip bag out of your “carry-on” bag, you notice it has noticeably “puffed up.” Airplane cabins are typically pressurized at 0.75 atm, and assuming the temperature inside an airplane is about the same as inside a potato chip processing plant, by what percentage has the bag “puffed up” in comparison to when it was packaged?

(II) A helium-filled balloon escapes a child’s hand at sea level and 20.0°C. When it reaches an altitude of 3600 m, where the temperature is 5.0°C and the pressure only 0.64 atm, how will its volume compare to that at sea level?

(I) Among the highest and lowest natural air temperatures ever recorded are 136°F in the Libyan desert and - 129° F in Antarctica. What are these temperatures on the Celsius scale?

"(I) What are the following temperatures on the Kelvin scale:                                                                                                                                      

 (a) 58°C?"

(III) An air bubble at the bottom of a lake 32.0 m deep has a volume of 1.00 cm³ . If the temperature at the bottom is 5.5°C and at the top 18.5°C, what is the radius of the bubble just before it reaches the surface?

(I) A thermometer tells you that you have a fever of 38.5°C. What is this in Fahrenheit?

(II) A helium balloon rises because of a buoyant force. By what percentage does the buoyant force on a helium balloon change if the temperature of the helium is increased from 15°C to 25°C while the temperature of the surrounding air is unchanged? Assume that the pressure of the helium remains constant.