Reference no: EM13799372
(1) Suppose you have 1 kg each of iron, glass, and water, and all three samples are at 10°C.
(a) Rank the samples from lowest to highest temperature after 100 J of energy is added to each by heat.
(b) Rank them from least to greatest amount of energy transferred by heat if enough energy is transferred so that each increases in temperature by 20°C.
(2) A steel strut near a ship's furnace is 2.00 m long, with a mass of 1.57 kg and cross-sectional area of 1.00 x 10-4 m2. During operation of the furnace, the strut absorbs a net thermal energy of 2.50 x 105 J.
(a) Find the change in temperature of the strut.
(b) Find the increase in length of the strut.
(c) If the strut is not allowed to expand because it's bolted at each end, find the compressional stress developed in the strut.
(3) Suppose a steel strut having a cross-sectional area 3.00 x 10-4 m2 and length 3.00 m is bolted between two rigid bulkheads in the engine room of a submarine. Assume the density of steel is the same as that of iron (7.86 x 103 kg/m3).
(a) Calculate the change in temperature of the strut if it absorbs an energy of 3.00 105 J of thermal energy.
(b) Calculate the compressional stress in the strut.
(4) Lake Erie contains roughly 4.00 ? 1011 m3 of water.
(a) How much energy is required to raise the temperature of that volume of water from 16.6°C to 22.2°C? (Assume the density of this water to be equal to that of water at 20°C and 1 atm.)
(b) How many years would it take to supply this amount of energy by using the 1,400-MW exhaust energy of an electric power plant?
(5) A 4.00-g copper coin at 22.5°C drops 40.0 m to the ground.
(a) Assuming 65.0% of the change in gravitational potential energy of the coin-Earth system goes into increasing the internal energy of the coin, determine the coin's final temperature.
(b) Does the result depend on the mass of the coin?
(6) A 5.00-kg block of ice at 0°C is added to an insulated container partially filled with 10.0 kg of water at 15.0°C.
(a) Find the final temperature, neglecting the heat capacity of the container.
(b) Find the mass of the ice that was melted.
(7) A 5.30 kg block of ice at 0°C is added to an insulated container partially filled with 10.3 kg of water at 15.0°C.
(a) Find the final temperature, neglecting the heat capacity of the container.
(b) Find the mass of the ice that was melted.
(8) If 7.90 kg of ice at -5.00°C is added to 12.0 kg of water at 15°C, compute the final temperature. How much ice remains, if any?
(9) A 54-g ice cube at 0°C is heated until 46.3 g has become water at 100°C and 7.7 g has become steam at 100°C. How much energy was added to accomplish the transformation?
(10) A 51-kg cross-country skier glides over snow as in the figure below. The coefficient of friction between skis and snow is 0.23. Assume all the snow beneath her skis is at 0°C and that all the internal energy generated by friction is added to snow, which sticks to her skis until it melts. How far would she have to ski to melt 1.5kg of snow?
(11) A steam pipe is covered with 1.50-cm thick insulating material of thermal conductivity of 2.00 ? 10-4 cal/cm · °C · s. How much energy is lost every second when the steam is at 220°C and the surrounding air is at 20.0°C? The pipe has a circumference of 800 cm and a length of 57.0 m. Neglect losses through the ends of the pipe.
(12) The filament of a 75-W light bulb is at a temperature of 2,450 K. Assuming the filament has an emissivity e = 0.6, find its surface area.