The simplest method is to measure the temperature of the mixture of water with any suitable thermometer. Suppose, starting to fill a bathtub or other container, you have put too hot water. Then, discovering his mistake, you immediately turned off the faucet of hot water and added a certain amount of cold. How to determine the final temperature? Thoroughly mix the water and use any suitable thermometer (e.g., medical).
You can also calculate the final temperature of the mixture in advance. Suppose you have a volume V1 of hot water with a temperature of t1. To it is added a quantity of cold water with the volume V2 and temperature t2. Want to calculate what the final temperature t will have a mixture. The heat loss to the environment can be neglected.
And heat capacity, and density of water at different temperatures the same. Therefore, the final temperature will depend on the volume ratio. It is easy to understand that in any case the final temperature t will be between t1 and t2, but less than the value of V2 compared to V1, the closer is t to t1, and Vice versa.
The final temperature t is calculated according to the following formula: t = (t1V1 + t2V2) / (V1 + V2). Substituting in this formula the values of temperatures and volumes, and performing calculations, you determine the desired temperature of the mix water.
Of course, your task would be solved in precisely the same manner, if instead of the volume you would have known mass of water, m1 and m2.
It is easy to understand that in the same way is the temperature of the mixture of any of the same liquids, not just water. If we are talking about the temperature of the mixture of different liquids, then the calculations must take into account their specific heat capacity, and that the simplified formula can not be applied.
Advice 2 : How to determine the temperature of the mixture
Although there is a perception that to feed from the bottle easier than the breast, moms of children iskusstvennomu face a number of nuances. For example, it is necessary each time to check the temperature of baby milk mixtureto inadvertently burn the baby.
To determine whether you have enough warmed baby milk mixture, you can "by eye", without the use of special measuring devices. Pour a small amount of milk on your wrist or inner part of the elbow where the skin is thin and delicate. The temperature of the mixture should be the same as body temperature or one degree above. If the temperature of the liquid is not there — to feed the baby. Cool too hot milk.
Heat a bottle of formula in the special electric heater for baby food. It will allow you to evenly heat the milk. Almost all heaters equipped with a thermostat and indicate the temperature of the food. In modern models by means of a handle or button you can set the desired temperature. Usually it is 37-38 degrees.
Thoroughly mix the bottle with the milk mixture, if you warmed it in the microwave — the milk can be heated unevenly. Some pediatricians recommend not to heat the mixture in a microwave oven as this may lead to loss of useful properties.
If you dilute the baby food with hot water, cool it to the desired temperature by putting the bottle in a bowl of cold water. Stir before giving milk to the child. Please note on the label: some types of special therapeutic infant formulas do not make very hot water.
Keep in mind that some babies prefer a certain temperature milk. Some are happy only drink very warm mixture, and the cooled refuse. Others like milk and yogurt at room temperature. Watching your baby, you will find the most acceptable temperature of the mixture.