Question: A 50-g cube of ice, initially at 0.00°C, is dropped into 200 g of water in an 80-g aluminum container, both initially at 30°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 x 10⁵ J/kg.) (9.5°C)

Answer Options:
8.0°C
9.5°C
10.0°C
12.0°C

Answer: 9.5°C

Question: 125 g of dry ice (solid CO₂) is dropped into a beaker containing 500 g of 66°C water. The dry ice converts directly to gas, leaving the solution. When the dry ice is gone, what is the temperature of the water? (Proposed correct answer is required as it’s not visible in the image)

Answer: 0°C

Question: 100 g of liquid nitrogen at its boiling point of 77 K is stirred into a beaker containing 500 g of 15°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 cal/g and the heat of fusion of water is 80 cal/g. (none)

Answer Options:
0 g
10 g
20 g
30 g

Answer: 0 g

Question: A windowpane is half a centimeter thick and has an area of 1.0 m². The temperature difference between the inside and outside surfaces of the pane is 15°C. What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s·m·°C.) (2 500 W)

Answer Options:
1 500 W
2 000 W
2 500 W
3 000 W

Answer: 2 500 W

Question: A 2.0-m² Thermopane window is constructed, using two layers of glass 4.0 mm thick, separated by an air space of 5.0 mm. If the temperature difference is 20°C from the inside of the house to the outside air, what is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s·m·°C and for air 0.023 4 J/s·m·°C.) (180 W)

Answer Options:
150 W
180 W
200 W
220 W

Answer: 180 W

Question: The thermal conductivity of aluminum is 238 J/s·m·°C and of copper is 397 J/s·m·°C. A rod of each material is used as a heat conductor. If the rods have the same geometry and are used between the same temperature differences for the same time interval, what is the ratio of the heat transferred by the aluminum to the heat transferred by the copper? (0.599)

Answer Options:
0.500
0.599
0.650
0.700

Answer: 0.599

Question: What is the emissivity of an ideal reflector? (0)

Answer Options:
0
0.5
1
2

Answer: 0

Question: Which type of heating causes sunburn? (radiation)

Answer Options:
Conduction
Convection
Radiation
Evaporation

Answer: Radiation

Question: An object at 27°C has its temperature increased to 37°C. The power then radiated by this object increases by how many percent? (14%)

Answer Options:
10%
12%
14%
16%

Answer: 14%

Question: In cloud formation, water vapor turns into water droplets which get bigger and bigger until it rains. This will cause the temperature of the air in the clouds to: a) become warmer, b) to become cooler, or c) to stay the same (no effect). (warmer)

Answer Options:
Warmer
Cooler
No effect

Answer: Warmer