Exam 16: Temperature and Heat

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1 and that of steel is 12 × 10^-6 K^-1.At 12°C a steel rod has a diameter of 2.540 cm and a copper pipe has a diameter of 2.536 cm.Which one of the following quantities is closest to the temperature to which the copper pipe must be heated in order for the unheated steel rod to fit snugly in the copper pipe?

A steel pipe 36.0 m long,installed when the temperature was Is used to transport superheated steam at a temperature of Steel's coefficient of linear expansion is .The pipe is allowed to expand freely when the steam is transported.What is the increase in the length of the pipe when it is used with the superheated steam?

The thermal conductivity of aluminum is twice that of brass.Two rods (one aluminum and the other brass)of the same length and cross-sectional area are joined together end to end.The free end of the brass rod is maintained at 0°C and the free end of the aluminum rod is maintained at 200°C.If no heat escapes from the sides of the rods,what is the temperature at the place where the two rods are joined together?

What is the net power radiated by a little animal with a surface area of 0.075 m² if his emissivity is 0.75,his skin temperature is 315 K,and he is in a room with a temperature of 290 K? (σ = 5.67 × 10^-8 W/m² ∙ K⁴)

Nitrogen boils at -196°C.What is the corresponding temperature in the Fahrenheit scale?

A glass flask has a volume of 500 mL at a temperature of 20° C.The flask contains 492 mL of mercury at an equilibrium temperature of 20°C.The temperature is raised until the mercury reaches the 500 mL reference mark.At what temperature does this occur? The coefficients of volume expansion of mercury and glass are 18 × 10^-5 K^-1 (mercury)and 2.0 × 10^-5 K^-1 (glass).

A lab assistant drops a 400.0-g piece of metal at 100.0°C into a 100.0-g aluminum cup containing 500.0 g of water at In a few minutes,she measures the final temperature of the system to be 40.0°C.What is the specific heat of the 400.0-g piece of metal,assuming that no significant heat is exchanged with the surroundings? The specific heat of this aluminum is 900.0 J/kg ∙ K and that of water is 4186 J/kg ∙ K.

If 150 kcal of heat raises the temperature of 2.0 kg of a material by 400°F,what is the specific heat capacity of the material?

Platinum melts at 3215°F.What is the corresponding temperature in the Kelvin scale?

A container of 114.0 g of water is heated using Of power,with perfect efficiency.How long will it take to raise the temperature of the water from To The specific heat capacity of the container is negligible,and the specific heat capacity of water is 4.186 × 10³ J/kg ∙ C.

A concrete wall of a cold storage room measures 3.0 m high,5.0 m wide,and 20 cm thick.The inside wall is to be covered by a layer of wood in order to reduce the rate of heat flow through the wall by 90 percent.The inner surface of the wooden wall is maintained at -10°C and the outer surface of the concrete wall is at 20°C.The thermal conductivities of concrete and wood are 0.80 W/m ∙ K (concrete)and 0.040 W/m ∙ K (wood).What is the temperature difference across the layer of wood?

In an electric furnace used for refining steel,the temperature is monitored by measuring the radiant power emitted through a small hole in the wall of the furnace,of area 0.5 cm².This hole acts like a perfect blackbody radiator having the same temperature as the interior of the furnace.If the temperature of the furnace (and therefore of the hole)is to be maintained at 1650°C,how much power will the hole radiate?

On a cold day,a piece of metal feels much colder to the touch than a piece of wood.This is due to the difference in which one of the following physical properties of these materials?

The temperature changes from 35°F during the night to 75°F during the day.What is the temperature change on the Celsius scale?

A person tries to heat up her bath water by adding 5.0 L of water at 80°C to 60 L of water at 30°C.What is the final temperature of the bath water?

By what primary heat transfer mechanism does the sun warm the earth?

A heat-conducting rod,0.90 m long and wrapped in insulation,is made of an aluminum section that is 0.20 m long and a copper section that is Long.Both sections have a cross-sectional area of The aluminum end and the copper end are maintained at temperatures of And Respectively.The thermal conductivities of aluminum and copper are 205 W/m ∙ K (aluminum)and 385 W/m ∙ K (copper).What is the temperature of the aluminum-copper junction in the rod with steady state heat flow?

Suppose that a rigid aluminum wire were to be strung out in a loop that just fits snugly around the equator (assuming a perfectly spherical Earth with a radius of 6.37 × 10⁶ m).If the temperature of the wire is increased by 0.50°C,and the increase in length is distributed equally over the entire length,how far off the ground will the wire loop be if it remained centered on the earth? The coefficient of linear expansion of aluminum is 24 × 10^-6 K^-1.

If 50 g of lead (of specific heat 0.11 kcal/kg ∙ °C)at 100°C is put into 75 g of water (of specific heat 1.0 kcal/kg ∙ °C)at 0°C.What is the final temperature of the mixture?

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1.A sheet of copper has a round hole with a radius of 3.0 m cut out of it.If the sheet is heated and undergoes a change in temperature of 80 K,what is the change in the radius of the hole?