Solution Found!
A refrigerator has a coefficient of performance
Chapter 20, Problem 11E(choose chapter or problem)
A refrigerator has a coefficient of performance of 2.25, runs on an input of 95 W of electrical power, and keeps its inside compartment at 5\(^\circ\)C. If you put a dozen 1.0-L, plastic bottles of water at 31\(^\circ\)C into this refrigerator, how long will it lake for them to be cooled down to 5\(^\circ\)C? (ignore any heat that leaves the plastic.)
Questions & Answers
QUESTION:
A refrigerator has a coefficient of performance of 2.25, runs on an input of 95 W of electrical power, and keeps its inside compartment at 5\(^\circ\)C. If you put a dozen 1.0-L, plastic bottles of water at 31\(^\circ\)C into this refrigerator, how long will it lake for them to be cooled down to 5\(^\circ\)C? (ignore any heat that leaves the plastic.)
ANSWER:Solution to 11E
Step 1
Performance co-efficient of refrigerator, K =2.25
Volume of a dozen 1L water bottles = 1x10-3m3 x 12=12x10-3 m3
Density of water =1g/cm3=103 kg/m3
Mass of of dozen of water bottles, m=12x10-3m x103kg/m3=12 kg
Initial temperature =310C =304k
Final Temperature =50C =278K
△T=(304-278)K=28K
Power =95W
W=95/t Joules