Exam 11: Energy in Thermal Processes

150 g of liquid nitrogen at its boiling point of 77.0 K is stirred into a beaker containing 510 g of 18.0°C water.If the nitrogen leaves the solution as soon as it turns to gas,how much water freezes? The heat of vaporization of nitrogen is 48.0 cal/g and that of water is 80.0 cal/g.

The first experiment,which systematically demonstrated the equivalence of mechanical energy and heat,was performed by

A metal bar is used to conduct heat.When the temperature at one end is 82.0°C and at the other is 37.0°C,heat is transferred at a rate of 9 J/s.If the temperature of the hotter end is reduced to 55.7°C,what will be the rate of heat transfer?

A windowpane is half a centimeter thick and has an area of 1.10 m².The temperature difference between the inside and outside surfaces of the pane is 19.0 °C.What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.840 J/s⋅m⋅°C. )

Of the planets with atmospheres,which is the warmest?

The tungsten filament of a light bulb has an operating temperature of about 2 050 K.If the emitting area of the filament is 0.70 cm²,and its emissivity is 0.68,what is the power output of the light bulb? (σ = 5.67 × 10−⁸ W/m²⋅K⁴)

What is the temperature increase of 3.00 kg of water when heated by a 900-W immersion heater for 9.00 min? (c_w = 4 186 J/kg⋅°C)

A slice of bread contains about 125 kcal.If specific heat of a person were 1.00 kcal/kg⋅°C,by how many °C would the temperature of a 65.0-kg person increase if all the energy in the bread were converted to heat?

The surfaces of a Dewar flask are silvered for the purpose of minimizing heat transfer by what process?

If one's hands are being warmed by holding them to one side of a flame,the predominant form of heat transfer is what process?

The Sun is a slightly variable star.What if the surface temperature of the Sun were to increase from 6 000 K to 6 100 K,what would be the increase in total power radiated assuming no other changes such as radius or emissivity?

Find the final equilibrium temperature when 20.0 g of milk at 15.0°C is added to 155.0 g of coffee at 89.0°C.(Assume the specific heats of coffee and milk are the same as water and neglect the heat capacity of the container. )c_water = 1.00 cal/g⋅°C = 4 186 J/kg⋅°C

Which of the following statements is true?

A 35.0-g cube of ice,initially at 0.0°C,is dropped into 180.0 g of water in an 70.0-g aluminum container,both initially at 35.0°C.What is the final equilibrium temperature? (Specific heat for aluminum is 900 J/kg⋅°C,the specific heat of water is 4 186 J/kg⋅°C,and L_f = 3.33 × 10⁵ J/kg. )

A cube of material with emissivity of 0.4 is heated from room temperature of 20°C to 100°C.The net power radiated by the cube is 20 W.What is the volume of the cube? (σ = 5.6696 × 10^-8 W/m^2·K⁴

Heat flow occurs between two bodies in thermal contact when they differ in what property?

Consider two different rods.The greatest thermal conductivity will be in the rod with

Sea breezes that occur near the shore are attributed to a difference between land and water with respect to what property?

Of the following systems,which contains the most heat?

Carbon dioxide and water molecules in the atmosphere will absorb