色花堂app

This demonstration visually compares the thermal conductivity of different materials. Four rods made with different materials (copper, aluminum, brass, and steel in order, clockwise) with holes to fit small candles are attached to a thermal conductometer. As heat from a Berenzomatic is applied to the center of the conductometer, heat conducts through each rod at different rates. These rates are dependent on the thermal conductivity ‘k’ of the material, the cross-sectional area ‘A’, the difference temperatures ‘ΔT’, and the length of the material ‘d’. The heat transferred per unit time is determined by Fourier’s Law:

Materials

Conductometer heat apparatus, candles, Bernzomatic torch, clay, laboratory jack, threaded rod, base, cardboard piece large enough to catch all candles, and a 90 degree clamp.

Setup

Performing the Demo

To perform the demonstration, unlock and ignite the torch while keeping it steady. Leave the torch lit until all the candles fall from the rods. The candles drop in order of decreasing thermal conductivity: copper, aluminum, brass, then steel.

Safety and Other Notes

Use caution after the demonstration, as the conductometer and Bernzomatic may be very hot. If using the manual setup, hold the conductometer by the handle since heat travels along the rod. To secure the candles, drip wax into each hole before inserting them.

Alternative Setup

This experiment can be performed manually with one or two people. One person holds the conductometer above the cardboard to catch the falling candles, while the other holds the Bernzomatic clear of the candles’ path.