Please Note: It may not always be possible to include the necessary special characters, superscripts, subscripts, etc. in e-mail responses to this group of exercises. We suggest that you discuss this matter with your professor/class and decide upon a system for indicating such characters. You may cut/paste some characters and/or Greek letters from Microsoft Word, using the Insert menu. Alternatively, we suggest that you agree upon abbreviations for or spell out symbols, Greek letters, or characters and indicate superscripts and subscripts by using "sup", "sub", or up/down carats.

m = 1.00 kg mw = 0.500 kg h = 5.00 m

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Determine the following:

1			Energy (in J) delivered to water Need a Hint?
2			Energy (in cal) delivered to water Need a Hint?
3			Temperature change (in °C) of water Need a Hint?

In a calorimetry experiment, 200 g of water is placed in a 150 g copper calorimeter cup. The cup and water have an initial temperature of 20°C and are well insulated from the surroundings. After 200 g of lead shot is heated to 100°C it is dumped into the water and an equilibrium temperature obtained.

4			Final equilibrium temperature of the system Need a Hint?
5			Heat gained by the water Need a Hint?
6			Heat gained by the calorimeter cup Need a Hint?
7			Total Heat gained by the water and calorimeter cup Need a Hint?
8			Total Heat lost by the lead shot Need a Hint?

Rods of aluminum, steel, and copper are welded together to form a Y-shaped object as shown below. The free end of the copper is maintained at 100°C, and the free ends of the aluminum and steel are maintained at 10.0°C. The rods are all 1.00 m long, have a cross-sectional area of 5.00 cm², and are insulated so that essentially no heat is lost from the surface.

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9			Temperature at the junction Need a Hint?
10			Rate (in J/s) at which heat flows along copper rod Need a Hint?
11			Temperature at midpoint of aluminum rod Need a Hint?

Approximate the living space of a residence by a 50.0 ft by 50.0 ft floor and ceiling with 8.00 ft. walls. Suppose the interior is maintained at 70.0°F while the exterior surfaces of walls and ceiling are exposed to a steady 10.0°F and the exterior surface of the floor remains at 40.0°F. The wall structure has an effective R-factor R_w = 10, the ceiling has R_c = 15, and the floor has R_f = 8, all in building industry units of °F·ft²/(BTU/h).

12			Heat current in the ceiling Need a Hint?
13			Heat current in the walls Need a Hint?
14			Heat current in the floor Need a Hint?
15			Heat loss to the outside in a 24.0 hr. period Need a Hint?
16			Cost of heating for 24.0 hrs. if fuel is purchased at 5.00 cents per 10,000 BTU

A glass of soda warms from 8.00°C to 12.00°C in 5.00 min. when the air temperature is 35.0°C. Assume the emissivity of the glass full of soda to be 0.800 and the area of the emitting surface to be 4.00 × 10^-2 m².

17			The rate at which the soda absorbs heat from the room while warming from 8.00°C to 12.0°C. Need a Hint?
18			The rate at which the soda loses heat to the room while warming from 8.00°C to 12.0°C. Need a Hint?
19			The net rate at which the soda gains energy by radiation while warming. Need a Hint?
20			Net heat gained by the soda in 10.0 min. Need a Hint?
21			Time for the soda to warm from 12.0°C to 18.0°C. Need a Hint?

The figure below shows a plot of temperature vs. heat energy supplied to 1.00 kg of some substance. The substance is a solid at temperatures lower than -10.0°C and a gas at temperatures above 20.0°C.

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22			Amount of heat energy needed to raise the temperature of the substance from -20.0°C to -10.0°C Need a Hint?
23			Specific heat of the substance as a solid Need a Hint?
24			Melting point for the substance Need a Hint?
25			Amount of heat required to melt the substance Need a Hint?
26			Latent heat of fusion for the substance Need a Hint?
27			Specific heat of the substance as a liquid Need a Hint?
28			Latent heat of vaporization for the substance Need a Hint?
29			Specific heat of the substance as a gas Need a Hint?