Question

A brass boiler has a base area of `0.15m^2` and thickness 1.0 cm it boils water at the rate of `6.0 kg//min`, When placed on a gas. Estimate the temperature of the part of the flame in contact with the boiler. Thermal conductivity of brass`=109 J//s-.^@C` ) and heat of vapourization of water `=2256 J//g`.

Answer 1

Let `T_1` be the temperature of the part of the flame in contact with boiler. The amount of heat flows into water in 1 min
`Q=KA(T_1-T_2)/(L)t`
`=(109xx0.15xx(T_1-100)xx60)/(0.01)J`
Mass of the water boiled in 1 min`=6kg=6000g`
Heat required to boil the water `Q=mL=6000xx2256J`
`(109xx0.15xx(T_1-100)xx60)/(0.01)=6000xx2256`
or `T_1-100=138`
or `T_1=238^@C`