$Cv=0\mathrm{.}120ca\frac{l}{g}c$

Heating rate: $Q=500W$

An electrical coil is used to heat $20kg$ of water in a closed well$-$insulated vessel. The water

is initially at $25C$ and $1$atm. The coil delivers a steady $3\mathrm{.}50kW$ of power to the vessel and

its contents. cloied system

$($a$)$ Write a differential energy balance on the water, assuming that $97\%$ of the energy

delivered by the coil goes into heating the water. What happens to the other $3\%?$

$($b$)$ Integrate the equation of Part$($a$)$ to derive an expression for the water temperature

as a function of time.

$($c$)$ How long will it take for the water to reach the normal boiling point? $(Cv=4\mathrm{.}2k\frac{j}{k}gC)$

A kettle containing $3$ liters of water at a temperature of $18C$ is placed on an electric stove

and begins to boil in four minutes. closed systen

$($a$)$ Write an energy balance on the water and determine an expression for $d\frac{T}{d}t,$