Question

The specific heat capacity of steel is 450 J/kg°C. If heat is added to 2 kg of steel for 30seconds, raising its temperature from 10°C to 32°C, what is the heat flow rate? Express your answer in W.

Answer 1

Given:

The specific heat capacity of steel is

$c=\text{ 450 J/kg }^{\circ}C$

The mass of the steel is m = 2 kg

The initial temperature of steel is

$T_i=\text{ 10}^{\circ}\text{ C}$

The final temperature of steel is

$T_f\text{ = 32}^{\circ}C$

The time is t = 30 s

To find the heat flow rate.

Explanation:

The heat flow rate can be calculated by the formula

$\frac{Q}{t}=\frac{mc(T_f-T_i)}{t}$

On substituting the value, the heat flow rate will be

$\begin{gathered} \frac{Q}{t}=\text{ }\frac{2\times450\times(32-10)}{30} \\ =\text{ 660 W} \end{gathered}$

Thus, the heat flow rate is 660 W.