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Hydrothermal vents deep on the ocean floor spout water at temperatures as high as 570°C. This temperature is below the boiling point of water because of the immense pressure at that depth. Because the surrounding ocean temperature is at 4.0°C, an organism could use the temperature gradient as a source of energy. (a) Assuming the specific heat of water under these conditions is 1.0 cal/g · °C, how much energy is released when 1.0 L of water is cooled from 570°C to 4.0°C? (b) What is the maximum usable energy an organism can extract from this energy source? (Assume the organism has some internal type of
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College Physics
- Beryllium has roughly one-half the specific heat of water (H2O). Rank the quantities of energy input required to produce the following changes from the largest to the smallest. In your ranking, note any cases of equality, (a) raising the temperature of 1 kg of H2O from 20C to 26C (b) raising the temperature of 2 kg of H2O from 20C to 23C (c) raising the temperature of 2 kg of H2O from 1C to 4C (d) raising the temperature of 2 kg of beryllium from 1C to 2C (e) raising the temperature of 2 kg of H2O from -1C to 2Carrow_forwardOverall, 80% of the energy used by the body must be eliminated as excess thermal energy and needs to be dissipated. The mechanisms of elimination are radiation, evaporation of sweat (2,430 kJ/kg), evaporation from the lungs (38 kJ/h), conduction, and convection.A person working out in a gym has a metabolic rate of 2,500 kJ/h. His body temperature is 37°C, and the outside temperature 26°C. Assume the skin has an area of 2.0 m2 and emissivity of 0.97. (σ = 5.6696 10-8 W/m2 · K4) (a) At what rate is his excess thermal energy dissipated by radiation? (Enter your answer to at least one decimal place.) W(b) If he eliminates 0.44 kg of perspiration during that hour, at what rate is thermal energy dissipated by evaporation of sweat? (Enter your answer to at least one decimal place.) W(c) At what rate is energy eliminated by evaporation from the lungs? (Enter your answer to at least one decimal place.) W(d) At what rate must the remaining excess energy be eliminated through conduction and…arrow_forwardWhen it rains, water vapor in the air condenses into liquid water, and energy is released. (a) How much energy is released when 0.0356 m (1.40 inch) of rain falls over an area of 2.59×106 m² (one square mile)? (b) If the average energy needed to heat one home for a year is 1.50x10¹1 J, how many homes could be heated for a year with the energy determined in part (a)? (a) Number i (b) Number 1 Units Unitsarrow_forward
- According to the USDA, an average, \moderately active" college student needs to eat 2500 calories per day. These \calories" are actually kilocalories, or kcal; and, we prefer to use Joules (J) in geophysics. The conversion is 1 kcal = 4187 J. The average geothermal heat ux is 60 mW/m2. How large an area on Earth's surface releases the same amount of energy in one day as used by the average college student in a day?arrow_forwardA ceiling area of 100 square meters consisting of four materials. The thermal insulation value of these materials from top to bottom is (0.6, 50, 0.7 and 0.45) square meters per watt per degree, respectively. If the external temperature is 5 degrees and the internal temperature is 20 degrees, what What is the speed of heat transfer through the wall?arrow_forwardA pronghorn antelope can run at a remarkable 18 m/sm/s for up to 10 minutes, almost triple the speed that an elite human runner can maintain. For a 32 kgkg pronghorn, this requires an astonishing 3.4 kWkW of metabolic power, which leads to a significant increase in body temperature. If the pronghorn had no way to exhaust heat to the environment, by how much would its body temperature increase during this run? (In fact, it will lose some heat, so the rise won't be this dramatic, but it will be quite noticeable, requiring adaptations that keep the pronghorn's brain cooler than its body in such circumstances.) Assume the efficiency of the pronghorn to be equal to that of human.arrow_forward
- A 46-kg woman eats a 522 Calorie (522 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut? 2192.4 X Your response is off by a multiple of ten. J (b) How many steps must the woman climb on a very tall stairway to change the gravitational potential energy of the woman-Earth system by a value equivalent to the food energy in one jelly doughnut? Assume the height of a single stair is 15 cm. 8.67 X Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. stairs (c) If the human body is only 26% efficient in converting chemical potential energy to mechanical energy, how many steps must the woman climb to work off her breakfast? 9 X Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. stairsarrow_forwardOverall, 80% of the energy used by the body must be eliminated as excess thermal energy and needs to be dissipated. The mechanisms of elimination are radiation, evaporation of sweat (2,430 kJ/kg), evaporation from the lungs (38 kJ/h), conduction, and convection. A person working out in a gym has a metabolic rate of 2,500 kJ/h. His body temperature is 37°C, and the outside 5.6696 x 10-8 W/m2 · K4) temperature 22°C. Assume the skin has an area of 2.0 m2 and emissivity of 0.97. (o %D (a) At what rate is his excess thermal energy dissipated by radiation? (Enter your answer to at least one decimal place.) 136.7 Your response differs from the correct answer by more than 10%. Double check your calculations. W (b) If he eliminates 0.44 kg of perspiration during that hour, at what rate is thermal energy dissipated by evaporation of sweat? (Enter your answer to at least one decimal place.) W (c) At what rate is energy eliminated by evaporation from the lungs? (Enter your answer to at least one…arrow_forwardA well-sealed room contains 60 kg of air at 200 kPa and 25°C. Now solar energy enters the room at an average rate of 0.8 kJ/s while a 120-W fan is turned on to circulate the air in the room. If heat transfer through the walls is negligible, the air temperature in the room in 30 min will bearrow_forward
- Large meteors sometimes strike the Earth, converting most of their kinetic energy into thermal energy. (a) What is the kinetic energy of a 109kg meteor moving at 25.0 km/s? (b) If this meteor lands in a deep ocean and 80% of its kinetic energy goes into heating water, how many kilograms of water could it raise by 5.0°C?arrow_forwardIn an electrically heated home, the temperature of the ground in contact with a concrete basement wall is 12.4 oC. The temperature at the inside surface of the wall is 18.4 oC. The wall is 0.13 m thick and has an area of 8.4 m2. Assume that one kilowatt hour of electrical energy costs $0.10. How many hours are required for one dollar's worth of energy to be conducted through the wall?arrow_forward
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