Heating


 * Heating**

We can increase the temperature of a lead block in three ways: 1. Mechanical working (hitting it!) 2. Electrical working (running a current through it) 3. **By heating it** (e.g. with your hands or a Bunsen burner)

When trying to heat a lead block the internal energy of the block will only increase if the block's temperature is less than the Bunsen burner flame or the person's hand.

Heating is different to working:

Working has nothing to do with temperature differences. It does not matter whether the lead block is hot or cold. You can still do work on the block by applying a force or passing a current through it.

Symbols:


 * U** = Internal energy
 * W** = Work
 * Q** = Energy gained (or lost) by heating

--> Some examples