A copper rod has a length of 1.7 m and a cross-sectional area of 3.2 × 10-4 m2. One end of the rod is in contact with boiling water and the other with a mixture of ice and water. What is the mass of ice per second that melts? Assume that no heat is lost through the side surface of the rod.

Respuesta :

Given :

A copper rod has a length of 1.7 m and a cross-sectional area of [tex]3.2 \times 10^{-4} \ m^2[/tex].

One end of the rod is in contact with boiling water and the other with a mixture of ice and water.

To Find :

The mass of ice per second that melts.

Solution :

Amount of heat transfer from boiling water to ice through the copper bar is :

[tex]Q = \dfrac{kA\Delta T }{L}\\\\Q = \dfrac{390\times 3.2 \times 10^{-4} \times 100}{1.7}\\\\Q = 7.34 \ J/s[/tex]

Let, amount of ice melts per second is :

[tex]m=\dfrac{Q}{L_f}[/tex]

Here, [tex]L_f[/tex] is the latent of fusion of water and is equal to [tex]L_f = 3.34\times 10^5 \ J/s[/tex].

Putting all values in above equation, we get :

[tex]m=\dfrac{7.34}{3.34\times 10^5}\\\\m = 2.19 \times 10^{-5} \ kg/s[/tex]

Hence, this is the required solution.