In life constantly it is necessary to regulate water temperature. What there was a speech about – whether to wash the dishes whether to take a bath. Both cold, and too hot water equally are not suitable for this purpose. Therefore, mixing different volumes of water with a different temperature, we bring it to optimum temperature.

## Instruction

1. The simplest method is to take temperature to water mix by means of any suitable thermometer. Let's assume, having begun to fill a bathtub or other capacity, you started up too hot water. Then, having found the oversight, you immediately blocked the gate of hot water and added a number of cold. How to determine total temperature? Carefully mix water and use any suitable thermometer (for example, medical).

2. You can also calculate the total temperature of mix in advance. Let's assume, you have a certain volume of V1 of hot water with t1 temperature. To it flowed a number of cold water with a volume of V2 and temperature of t2. It is required to calculate what total temperature of t mix will have. Losses of heat to the environment can be neglected.

3. Both thermal capacity, and density of water of different temperature is identical. Therefore, total temperature will depend on a ratio of volumes. It is easily possible to understand that anyway the total temperature of t will be intermediate between t1 and t2, but the less size V2 in comparison with V1, the will be closer than t to t1 and vice versa.

4. Total temperature of t is calculated by the following formula: t = (t1V1 + t2V2) / (V1 + V2). Having substituted sizes of temperatures and volumes known to you in this formula, and having made calculations, you determine the required temperature of mix of water.

5. Certainly, your problem would be solved absolutely the same way if instead of volumes the mass of m1 and m2 water is known to you.