3296 iPad 11:21 PM D.Gray-Man 32 Read D. x Mastering Physics: Ass x MasteringPhy

Question

3296 iPad 11:21 PM D.Gray-Man 32 Read D. x Mastering Physics: Ass x MasteringPhysics: Hw11 x C D session masteringphysics.com/myct/itemView?assignmentProblemlD 39515747&offset; next Physics for Sciences 1 Signed in as charley correa Helg Close Resources Problem 12.35 previous l 5 of 8 l next D Problem 12.35 A tub containing 60kg of water is placed in a farmer's canning cellar, initially at 12 C. On a cold evening the cellar loses thermal energy through the walls at a rate of 1200J/s. Without the tub of water, the fruit would freeze in 4 h (the fruit freezes a 1 °C because the sugar in the fruit lowers the freezing temperature). Part A By what time interval does the presence of the water delay the freezing of the fruit? The heat of fusion for water at 0 C is Ly 3.35x10 J/kg.The specific heat of water is c 4180 J/kg C Express your answer to two significant figures and include the appropriate units. At delay Value Units Submit My Answers Give Up Incorrect; Try Again; 3 attempts remaining Provide Feedback Continue

Explanation / Answer

Q = QLOSS = ( QL ) * ( t )
Q = ( 1200 J/s ) ( 4 h ) ( 3600 s/h ) = 17.28 x 106 J
Q = 17280 kJ

Now get heat loss to take the 60 kg of water from 12 C to ice at -1 C , QW

QW = ( mW ) ( CsnW ) ( 12.0 C - 0.0 C ) + ( mW ) ( h subW ) + ( mW ) ( CshICE ) ( 0.0 + 1.0 )

QW = ( 60 kg ) ( 4.180 kJ/kg ) ( 12.0 C ) + ( 60 kg ) ( 335 kJ/kg ) + ( 60 kg ) ( 2.10 kJ/kg-C ) ( 1.0 C )

QW = 3009.6 kJ + 20100 kJ + 126 kJ = 23235.6 kJ

Delta t = QW / QL
Delta t = 23235.6 kJ / 1.2 kJ/s = 19363 s
delta tdelay = 5.38 hours

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.