You are working on a summer job at a company that designs non-traditional energy systems. The company is working on a proposed electric power plant that would make use of the temperature gradient in the ocean. The system includes a
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- A thermal engine produces 4 MJ of electrical energy while operating between two thermal baths of different temperatures. The working substance of the engine discharges 5 MJ of heat to the cold temperature bath. What is the efficiency of the engine?arrow_forwardWater near the surface of a tropical ocean has a temperature of 298.2 K (25.0°C), while water 700 m beneath the surface has a temperature of 280.2 K (7.0 °C). It has been proposed that the warm water be used as the hot reservoir and the cool water as the cold reservoir of a heat engine. Find the maximum possible efficiency for such an engine.arrow_forwardYou are hired to build a geothermal power plant that absorbs heat from a hot water spring and discards heat into the surrounding air, which is at a temperature of 17°. The plant is designed for a maximum (Carnot) efficiency of 0.21. What is the temperature, in degrees Celsius, of the hot water gushing from the spring? If the rate of energy supplied to the plant by the hot-water source is 4.6 kW, what is the plant’s maximum rate of power output, in kilowatts?arrow_forward
- A coal-fired power station is a huge heat engine. It uses heat transfer from burning coal to do work to turn turbines, which are used to generate electricity. In a single day, a large coal power station has 2.50×1014 J of heat transfer from coal and 1.48×1014 J of heat transfer into the environment. (a) What is the work done by the power station? (b) What is the efficiency of the power station?(c) In the combustion process, the following chemical reaction occurs: C + O2 → CO2 .This implies that every 12 kg of coal puts 12 kg + 16 kg + 16 kg = 44 kg of carbon dioxide into the atmosphere. Assuming that 1 kg of coal can provide 2.5×106 J of heat transfer upon combustion, how much CO2 is emitted per day by this power plant?arrow_forwardA particular power plant operates with a heat-source reservoir at 350°C and a heatsink reservoir at 30°C. It has a thermal efficiency equal to 55% of the Carnot-engine thermal efficiency for the same temperatures. What is the thermal efficiency of the plant? To what temperature must the heat-source reservoir be raised to increase the thermal efficiency of the plant to 35%? Again, η is 55% of the Carnot-engine valuearrow_forwardA homeowner is trying to decide between a highefficiency natural gas furnace with an efficiency of 97 percent and a ground-source heat pump with a COP of 3.5. The unit costs of electricity and natural gas are $0.115/kWh and $1.42/therm (1 therm = 105,500 kJ). Determine which system will have a lower energy cost.arrow_forward
- As a gasoline engine is running, the amount of gasoline containing 15,000J of chemical potential energy is burned in 1 s. During that second, the engine does 3,000J of work. The burning gasoline has a temperature of about 2500 K. The waste heat from the engine flows into the air at about 300 K. What is the Carnot efficiency of a heat engine operating between these two temperatures?arrow_forwardA water treatment plant has three flocculation compartments that water flows though sequentially (in series). The water is gently mixed in each compartment with rotating paddles, and the power input decreases as water moves through each compartment: Compartment #1: 186 W; Compartment #2: 30.0 W; Compartment #3: 7.50 W. Each compartment is 4.17 m deep, 3.75 m wide, and 4.17 m long. The water temperature is 15 °C the flow rate is 16,000 m3/day. Calculate the velocity gradient for each compartment.arrow_forwardOne of the most efficient engines ever built is a coal-fired steam turbine engine in the Ohio River valley, driving an electric generator as it operates between 1870°C and 430°C. (a) What is its maximum theoretical efficiency? (b) Its actual efficiency is 42.0%. How much mechanical power does the engine deliver if it absorbs 1.40 x 105 J of energy each second from the hot reservoir.arrow_forward
- A heat engine operates between two temperatures such that the working substance of the engine absorbs 5000 J of heat from the high-temperature bath and discharges 3000 J to the low-temperature bath. The rest of the energy is converted into mechanical energy of the turbine. Find (a) the amount of work produced by the engine and (b) the efficiency of the engine.arrow_forwardA heat pump moves heat from the chilly 8°C air outside a house to the toastier 21°C air inside. The actual coefficient of performance of the system is 3.2, a typical value. How much energy would it take to add 11 kJ each second if the heat pump ran at the maximum theoretical efficiency?arrow_forwardSuppose a heat engine is connected to two energy reservoirs, one a pool of molten aluminum (660°C) and the other a block of solid mercury (−38.9°C). The engine runs by freezing 1.40 g of aluminum and melting 16.0 g of mercury during each cycle. The heat of fusion of aluminum is 3.97 105 J/kg; the heat of fusion of mercury is 1.18 104 J/kg. What is the efficiency of this engine? %arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning