How Much Heat Per Second H (=qδt) Flows From The Boiling Water To The Ice-water Mixture?

The ability for heat to flow from a warmer substance to a cooler one is an important property of nature. In physics, this phenomenon is called thermal conductivity, and it is one of the fundamental properties of matter.

When thermal conductivity is discussed, two substances are usually compared: gases and liquids versus solids. For the most part, gases have higher thermal conductivity than liquids and solids have the lowest of the three.

When discussing melting ice, the influence of thermal conductivity on the rate of melting can be explored. How much heat per second (q) flows from the boiling water to the ice-water mixture? How fast will the ice melt? These are fascinating questions to answer!

This article will discuss how to answer these questions and how to experimentally determine the amount of heat per second that flows from the boiling water to the ice-water mixture.

Calculate heat capacity of water

Now let’s go back to our original question.

How much heat per second flows from the boiling water to the ice-water mixture?

We already calculated q, the amount of heat transferred from the boiling water to the ice-water mixture, so all we need to do is calculate how much time this transfer occurs for.

There are two times that matter: how long it takes for the water to change temperatures, and how long it takes for all of the water to turn into ice. We will have to take into account both of these times when calculating q!

The time it takes for the whole mixture to change temperatures is about one minute. Given that, we can calculate q using this formula: = /, where is the heat capacity of water (4186 J/(kg·°C)), and is one minute. So we get: = 4186 J/(kg·°C) × 1 min = 4186 J/kg.

Calculate mass of water

To calculate the mass of water in the kettle, you need to know the volume of the water in the kettle and the density of water. You can find these specifications in online resources such as Wikipedia.

The volume of the water in the kettle can be calculated by first calculating the volume of the empty kettle using cylinder formula V=πr2h, where r is radius and h is height, then adding the volume of water.

The density of water can be calculated by first weighing the empty kettle then adding water up to a certain level and then again weighing it. Density = mass/volume.

Calculate heat transfer rate from boiling water to ice-water mixture

Now let’s find out how much heat per second flows from the boiling water to the ice-water mixture.

We know that the total heat transferred is equal to the rate of heat transfer by conduction multiplied by the length of time the experiment is conducted. So we need to find the time it takes for both layers to reach equilibrium.

The time it takes for both layers to reach equilibrium is t=Δt/v, where Δt is the difference between the temperatures of the two layers, and v is the average velocity of molecules in each layer. We can calculate v using kinetic theory.

So, we have: Total heat transferred=Rate of conduction×Time taken for both layers to reach equilibrium=(qδt)=0 (1)Where q=mass of water in kilogram, δ=density of water, t=time taken for both layers to reach equilibrium in seconds, n=average velocity of molecules in a given layer.

Interpret results

The ratio of heat transfer due to convection and radiation is important to know. If the temperature of the ice mixture is lower than the boiling point of water, then convection is no longer a factor and only radiation remains.

You can test this yourself by placing a pot of water on a stove at high heat and then putting a pot of ice on top of it. You will see that the ice melts quickly and evenly, indicating that thermal energy is being transferred through radiation.

This is an important fact to recognize in heating or cooling systems where there is an aim to transfer thermal energy from one medium to another. In such cases, insulating materials should be used to prevent convection, or the material used should have low thermal conductivity in order to better preserve the desired effect.

Your results showed that there was significant radiation in your experiment, which was not expected! It is important to recognize your errors so that you can improve your future experiments.