Problem 5 Entropy changes A 1000kg ice sculpture of the great physicist Lord Kelvin is lost overboard a pleasure boat floating on a large lake (Tiake= 27 °C). The ice is at a temperature of 0°C. By the time the sculpture is recovered, some of the ice has melted so that only 900kg of ice remains. For this entire problem, assume that the water resulting from the melted ice stays at 0 °C and does not have sufficient time to warm up to 27 °C. You may approximate the heat of fusion for water as Lf= 300 kJ/kg. a) During this time, how much heat, Q, was exchanged between the lake and the sculpture? Clearly indicate whether heat was added or removed from the ice. b) What is the change in entropy of the sculpture? (Consider the water melted from the ice as part of the sculpture.) c) How much has the entropy of the lake (not including the sculpture) changed during this time? d) What is the net change of the entropy of the whole universe due to this process? Please explicitly state whether this is positive, negative or zero.

Problem 5 Entropy changes A 1000kg ice sculpture of the great physicist Lord Kelvin is lost overboard a pleasure boat floating on a large lake (Tiake= 27 °C). The ice is at a temperature of 0°C. By the time the sculpture is recovered, some of the ice has melted so that only 900kg of ice remains. For this entire problem, assume that the water resulting from the melted ice stays at 0 °C and does not have sufficient time to warm up to 27 °C. You may approximate the heat of fusion for water as Lf= 300 kJ/kg. a) During this time, how much heat, Q, was exchanged between the lake and the sculpture? Clearly indicate whether heat was added or removed from the ice. b) What is the change in entropy of the sculpture? (Consider the water melted from the ice as part of the sculpture.) c) How much has the entropy of the lake (not including the sculpture) changed during this time? d) What is the net change of the entropy of the whole universe due to this process? Please explicitly state whether this is positive, negative or zero.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.4DP

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