Heat and Thermal ExpansionHard
Question
A cup of tea cools from 80oC to 60oC in one minute.the ambient temperature is 30oC. In cooling from 60oC to 50oC. will take :-
Options
A.50 s
B.90 s
C.60 s
D.48 s
Solution
Newton′s law of Cooling 
= k[θ - θ0]
θ0 = surrounding′s temperature
⇒
.....(1)
and
.....(2)
⇒ t = 48 sec
= k[θ - θ0]θ0 = surrounding′s temperature
⇒
.....(1)and
.....(2)⇒ t = 48 sec
Create a free account to view solution
View Solution FreeMore Heat and Thermal Expansion Questions
If water at 0oC , kept in a container with an open top, is placed in a large evacuated chamber :-...During the melting of a slab of ice at 273 K at atmosphere pressure : -...A sample of gas follows process represented by PV2 = constant. Bulk modulus for this process is B, then which the of the...Ice starts forming in like with water at 0oC when the temperature is - 10oC. If the taken for 1 cm of ice be 7 hours, th...During experiment, an ideal gas is found to obey a condition P2/ρ = constant [ρ density of the gas]. The gas i...