Page 236 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 18] HEAT 221

(a) 1 kg each of ice at 0 C and steam at 100 C
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(b) 1 kg each of ice at 0 C and water at 100 C
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(c) 1 kg each of water at 0 C and steam at 100 C
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(d) 1 kg each of water at 0 C and water at 100 C
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18.16. If 3 MJ of heat is removed from 1 kg of steam at 200 C, the result is
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(a) ice (c) water
(b) water and ice (d) water and steam
Supplementary Problems

18.1. A glass of water is stirred and then allowed to stand until the water stops moving. What has happened to the kinetic
energy of the moving water?

18.2. Why is an ice cube at 0 C more effective in cooling a drink than the same mass of water at 0 C?
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18.3. Ethyl alcohol melts at −114 C and boils at 78 C. What are the Fahrenheit equivalents of these temperatures?
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18.4. Bromine melts at 19 F and boils at 140 F. What are the Celsius equivalents of these temperatures?
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18.5. How much heat must be removed from 4 lb of water to 200 F to reduce its temperature to 50 F?
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18.6. How many joules of heat must be removed from 2 kg of water at 90 C to reduce its temperature to 20 C?
18.7. How many kilocalories of heat must be added to a 20-kg block of ice to raise its temperature from −20 to −5 C?
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18.8. How much heat is lost by a 50-g silver spoon when it is cooled from 20 to 0 C?
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18.9. Three thousand kilojoules of heat is added to a 100-kg statue of Isaac Newton initially at 18 C. What is its final
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temperature [c statue = 0.58 kJ/(kg· C)]?
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18.10. Two kilojoules of heat is added to a 0.88-kg glass jar at 20 C, and its temperature is found to rise to 28 C. What is
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the specific heat capacity of the glass?
18.11. Ten kilograms of water at 5 C is added to 100 kg of water at 80 C. What is the final temperature of the mixture?
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18.12. A 600-g copper dish contains 1500 g of water at 20 C. A 100-g iron bar at 120 C is dropped into the water. What is
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the final temperature of the water [c copper = 0.39 kJ/(kg· C); c iron = 0.46 KJ/(kg· C)]?
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18.13. Four pounds of soup at 140 F is poured into a 4-lb china serving dish at 70 F. What is the final temperature of the
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soup [c soup = 0.9 Btu/(lb· F); c dish = 0.2 Btu/(lb· F)]?
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18.14. How much water at 20 C must be added to 5 kg of punch at 70 C that is in a 1.5-kg silver punch bowl to lower its
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temperature to 60 C[c punch = 2.93 kJ/(kg· C); c silver = 0.234 kJ/(kg· C)]?
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18.15. How much heat must be removed from 200 g of water at 30 C to convert it to ice at 0 C?
18.16. Three pounds of water at 100 F is poured on a large block of ice at 32 F. How much ice melts?
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18.17. Two thousand kilojoules of heat is added to 10 kg of zinc at 20 C. How much zinc melts? The specific heat capacity
of zinc is 0.39 kJ/(kg· C), it melts at 420 C, and its heat of fusion is 100 kJ/kg.
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18.18. How much ice at 0 C must be added to 200 g of water at 30 C to lower its temperature to 20 C?