====== 6. Heat transfer in metals ======

===== - Introduction =====
The goal of this experiment is to measure the **rate of heat transfer** of copper and steel and compare. The rate of heat transfer

$$ H = \frac{k A \Delta T}{L} $$

where $k$ is **thermal conductivity** which has the units [W m$^{-1}$ K$^{-1}$], $A$ is the cross-sectional area of the conductor, $L$ is its length and $\Delta T$ is the difference in temperature between the two ends of the conductor.

The thermal conductivity of copper and steel are given below.

^ Material ^ Thermal conductivity [W m$^{-1}$ K$^{-1}$] ^
| Copper (Cu) | $401$ |
| Steel (Fe+C) | $14$ |

===== - Method and data =====
==== - List of apparatus ====
  - Beaker
  - Thermometer
  - Substance (Copper, Steel)
  - Weighing scale
  - Water (20 ml)

==== - Setup and Procedure ====

Using a Vernier calipers measure the radius of the rods and from the radius ($r$) calculate $A=\pi r^2$.

Using a thread and a meter scale measure the length $L$ of the rods.

==== - Data table ====
Measure the temperature changes and note down in the following table.

^ Time [minute] ^ Temperature of Copper [$^\circ$C] ^ Temperature of Steel [$^\circ$C] ^
| 0 |  |  |
| 1 |  |  |
| 2 |  |  |
| 3 |  |  |
| 4 |  |  |
| 5 |  |  |


===== - Graphical analysis =====

===== - Heat transfer =====
Compare $H_c$ and $H_s$ in units of J min$^{-1}$.
===== - Discussion and conclusion =====