INTRO OF HEAT

 HEAT

In 18th and beginning of 19th century heat was considered was weight less fluid according to the caloric theory the hot body contains more caloric then the cold bodies.

Count Rumford Challenge on Caloric concept

In 1798 count Rumford (Benjamin) challenge the concept heat fluid. Count Rumford concluded that the heat is produced by friction while is caused by friction.

James   Joules Experiment On Heat

1840 James Joule support the theory of Count Rumford that:

Ø  Heat is not as the flow of substance (calorie).

Ø  Heat is the form of energy flow from hot body to cold body.

Ø  Heat is the form of energy that transfer body because of temperature’s difference.

Definition

“Heat is the sum of kinetic energy of all molecules or atoms of body system.”

Once the heat is transferred into body it will converted internal energy.

According to the kinetic theory of the molecule. The Molecules of the body always be in motion. The motion of the molecule is due to the kinetic energy which possessed by the molecule.

            Then the sum of the kinetic energy of all the molecules is called “Heat”.

INTERNAL ENERGY

                                All type of energies like K.E, P.E, Transnational, Rotational energy along with binding energies of nuclear energy called as internal of the heat also can be define as the energy evolved in care of combustion reaction, exothermic reaction, fission, fusion reaction but from high temperature to low temperature.

Differentiate between the heat and temperature

 Differentiate between the heat and temperature

 

Heat	Temperature
Heat is the form of energy us transit from one body to another due to temperature difference.	Temperature is the degree of hotness or coldness.
It is the total kinetic energy of the body.	It is the average kinetic energy of the body.
It’s unit is Joule	It’s units are oC, oF, and oK

ANOMALOUS EXPANSION OF WATER

 ANOMALOUS EXPANSION OF WATER

Most of the liquids expands on heating while contract on cooling. However, water at 0oC when heated, starts contracting on heating instead of expanding. After 4oC it starts expanding on heating normally like other liquids. It is also seen that hot water when cooled up to 4oC and its density increases.

However, further on from 4oC to 0oC it expands. At 0 oC the water changes in to ice. Due to expansion, the density of it at 0 oC becomes less than water so ice floats on water. At 0 oC water has maximum density and least volume. This is called anomalous or irregular behavior  behavior of water.

Effect of Anomalous Expansion of Water.

In colder climate, when the atmospheric temperature starts falling. The density of water in seas and lakes starts to rise reaching to maximum at 4 degree Celsius. This heavier water at 4 degree Celsius goes to lower depths and replace by warmer water. The process goes on till all the water in the lakes acquires a uniform temperature if 4 degree Celsius. if the atmospheric temperature continues falling below 4 degree Celsius, the water starts expanding and begin lighter it does not sink down. At reaching 4 degree Celsius , waters freezes on the surface but the water below the ice remain at 4 degree Celsius. Since ice a bad conductor of heat, it does not allows the heat contained in water below to escape into the atmosphere through the ice sheet. As a result even in the coldest season, the water at lower depths remain in liquid form, providing life to aquatic animals.