Scalar and Vector Quantities

We have learnt in previous posts that, in physics, quantities are properties or values that can be measured. Measurement is very important in science as it is usually a means of communication by scientists and engineers. These quantities are categorized as fundamental/basic quantities (length, mass, time, electric current etc.) and derived quantities (such as volume, area, density, force, pressure and so on).

However, these quantities can further be classified into two: Scalars and Vector quantities.

Applications of Thermal Expansion

 

The knowledge of the principle of thermal expansion of solids have been helpful in construction of some buildings, bridges, railway lines, telephone wires, the bimetallic strip in electric iron, electric fire alarm and so on. Let's take a look at some of the applications of thermal expansion in solids:

Thermal Expansivity

We have learnt in previous lessons that when heat is applied to most solids and liquids, they expand, that is, they increase in size. There may be an increase in length, area or volume of the solid. This is because according to kinetic theory, when an object is heated, the molecules gain more kinetic energy to move around and thus increasing their displacement about their mean positions.

Expansion in solids

Always remember that solids expand when heat is applied and

Practical applications of heat transfer methods

 

In the last lesson, we learnt the three modes of heat transfer with examples. Here, we shall look at how these mode of heat transfer can be applied to our everyday life.

Heat transfer

 

In the previous post about heat and temperature, we established that heat flows from a hotter body to a cooler body and not the reverse. In this lesson, we shall learn three different ways by which heat can be transferred depending on the medium. Heat transfer can occur in three ways which are: conduction, convection and

Concept of Heat and Temperature

When a cold body is brought near a hot body, after some minutes, you will discover that the cold body becomes warm. This is as a result of heat transfer from the hot body to the cold body due to their temperature difference. It is important to note that heat always flows from a hot body to a cold body and not the reverse. This phenomenon can also be observed when you place a kettle of cold water on a hot stove. Heat is therefore transferred from the hot stove to the

Concept of Power

Power can be defined as the time rate of doing work. This means that how much power expended by a body depends on how much work is done and how fast it is done.

If two men of the same weight are to lift a load of 50kg up a flight of stairs of the same height, the man who gets to the top of the stairs first has the greater power. This is because