The device shown in Figure CQ22.7, called a thermoelectric converter, uses a series of semiconductor cells to transform internal energy to electric potential energy, which we will study in Chapter 25. In the photograph on the left, both legs of the device are at the same temperature and no electric potential energy is produced. When one leg is at a higher temperature than the other as shown in the photograph on the right, however, electric potential energy is produced as the device extracts energy from the hot reservoir and drives a small electric motor. (a) Why is the difference in temperature necessary to produce electric potential energy in this demonstration? (b) In what sense does this intriguing experiment demonstrate the second law of
Figure CQ22.7
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Physics for Scientists and Engineers With Modern Physics
- The device shown in Figure CQ22.7, called a thermoelectric converter, uses a series of semiconductor cells to transform internal energy to electric potential energy, which we will study in Chapter 25. In the photograph on the left, both legs of the device are at the same temperature and no electric potential energy is produced. When one leg is at a higher temperature than the other as shown in the photograph on the right, however, electric potential energy is produced as the device extracts energy from the hot reservoir and drives a small electric motor. (a) Why is the difference in temperature necessary to produce electric potential energy in this demonstration? (b) In what sense does this intriguing experiment demonstrate the second law of thermodynamics?arrow_forwardHow much energy does Hannah the Standard Poodle absorb from the sun during a 37-minute walk? Hannah’s fur is matte black, so she absorbs nearly all of the sunlight that hits her; from above, she looks approximately like a rectangle that is 92 cm long and 32 cm wide. The solar intensity in Hannah’s Orange County neighborhood is 1200 W/m2.arrow_forwardThe filament in a light bulb has a diameter of 0.02 mm and an emissivity of 1.0. The temperature of the filament is 3×1000°C. What should be the length of the filament in meters so it will radiate 60 W of power? The Stefan-Boltzmann constant is 5.670 × 10-8 W/m2 · K4. Please give your answer with 3 decimal places.arrow_forward
- An insulated beaker with negligible mass contains a mass of 0.300 kg of water at a temperature of 66.1°C. Take the specific heat for water to be 4190 J/kg - K the specific heat for ice to be 2100 J/kg · K and the heat of fusion for water to be 334 kJ/kg. Part A For related problem-solving tips and strategies, you may want to view a Video Tutor Solution of Changes in both temperature and phase. How many kilograms of ice at a temperature of -20.5°C must be dropped in the water to make the final temperature of the system 23.2°C? Express your answer in kilograms. ΑΣΦ ? Mice = kg Submit Previous Answers Request Answerarrow_forwardConsider the process shown in (Figure 1). Figure p (kPa) 400- 200- Screenshot 0 100 200 300 1 of 1 V (cm³) Part A How much work is done on the gas in this process? Express your answer with the appropriate units. - HÅ W = Submit Value Provide Feedback Request Answer Units **** ?arrow_forwardAn electric generator at a power plant produces energy by passing superheated steam from a high temperature container (reservoir), through a pipe connected to a series of fans, and then into a low temperature reservoir. As the steam passes across the blades of the fans some of the heat energy of the steam is transformed into mechanical energy, which turns the fans which in turn are connected to a generator, which in turn converts the mechanical energy into electrical energy. If the high temperature steam has a temperature of 376 K and the low temperature reservoir has a temperature of 101.9 K, what is the Carnot efficiency of this process?arrow_forward
- A baking dish is removed from a hot oven and placed on a cooling rack. As the dish cools down to 31.0°C from 189°C, its net radiant power decreases to 13.0 W. What was the net radiant power of the baking dish when it was first removed from the oven? Assume that the temperature in the kitchen remains at 24.0°C as the dish cools.arrow_forwardA worker drives a 0.500 kg spike into a rail tie with a 2.50 kg sledgehammer. The hammer hits the spike with a speed of 65.0 m/s. If one-third of the hammer’s kinetic energy is converted to internal energy of the hammer and the spike, how much does the total internal energy increase?arrow_forwardYou have two rods of the same length and diameter, but they are formed from different materials. The rods are used to connect two regions at different temperatures so that energy transfers through the rods by heat. They can be connected in series as shown or in parallel as shown. In which case is the rate of energy transfer by heat larger? (a) The rate is larger when the rods are in series. (b) The rate is larger when the rods are in parallel. (c) The rate is the same in both cases.arrow_forward
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