# Physics

## VISCOSITY

MEANING OF VISCOSITY Viscosity is the internal friction which exists between layers of the molecules of a fluid (liquid or gas) in motion. The viscosity of a fluid can also be defined as the measure of how resistive the fluid is to flow. It is a vector quantity & measured in pascal-seconds(pa.s). It can be […]

## WORK, ENERGY AND POWER

WORK Work is said to be done whenever a force moves a body through a certain distance in the direction of force.  Work done can be defined mathematically as the product of the force and the displacement. It is a scalar quantity & measured in Joules W = F X d ……………………………………….1. W = mgh

## PRESSURE, ARCHIMEDES’ PRINCIPLES, UPTHRUST & LAWS OF FLOATATION

PRESSURE Pressure is defined as the perpendicular force per unit area acting on a surface. It is a scalar quantity & measured in N/m2 or Pascal (pa).It can also be defined as the force per unit area, which is calculated by taking the total force and dividing it by the area over which the force

## DENSITY & RELATIVE DENSITY

DEFINITION OF DENSITY The density of a substance is the mass per unit volume of the substance. Density = mass of a given substance Volume of the substance Density is scalar quantity& measured in kgm-3 (kilogram per cubic meter)   Determination of Density The determination of density involves the determination of a mass and a

## VECTOR & SCALAR QUANTITY, DISTANCE/DISPLACEMENT

VECTOR & SCALAR QUANTITY, DISTANCE/DISPLACEMENT, SPEED/VELOCITY, ACCELERATION, DISTANCE/DISPLACEMENT –TIME GRAPH, SPEED/VELOCITY–TIME GRAPH SCALAR & VECTOR QUANTITY A scalar quantity is defined as a quantity that has magnitude only but no direction. Typical examples of scalar quantities are time, distance, speed, temperature, volume, work, power, electric potential etc.  A scalar quantity or parameter has no directional

## FRICTION

DEFINITION OF FRICTION Friction (Fr) is defined as a force which acts at the surface of separation between two objects or two bodies in contact and tend to oppose the motion of one over the other. It is simply force of opposition. We have two types of friction: (a) Static friction, Fs (b) Dynamic friction,

## MOTION IN NATURE

FUNDAMENTALS OF MOTION Many scientists have studied motion and its properties because of its importance to life. The Italian, Galileo Galilei, who lived from 1564 to 1642, did the first systematic study of motion. The science of the study of motion done by Galileo is known as kinematics. Isaac Newton was another scientist who did

## MEASUREMENT OF MASS, WEIGHT, LENGTH & TIME

TECHNIQUES AND MEASUREMENT Measurement is an important aspect of physics or other sciences. No fact in science is accepted, no law is established, unless it can be exactly measured and quantified. As physics is based on exact measurements, every such measurement requires two things; first a number or quantity, secondly a unit, e.g. 20 metres

## INTRODUCTION TO PHYSICS

MEANING OF PHYSICS Physics is the scientific study of matter and energy and how they interact with each other. This energy can take the form of motion, light, electricity, radiation, gravity etc. Physics deals with matter on scales ranging from sub-atomic particles (i.e. the particles that make up the atom and the particles that make

## MACHINES

Machines make our work simpler. It is a force producing device by which a large force called load can be overcome by a small applied force called effort Terminologies Used In Machines FORCE RATIO (MECHANICAL ADVANTAGE ) VELOCITY RATIO EFFICIENCY MECHANICAL ADVANTAGE We define effort as the force applied to a machine and load as

## SIMPLE HARMONIC MOTION

This is the periodic motion  of  a body or particle  along a straight  line  such that the acceleration of  the body  is directed  towards  a fixed  point . A particle undergoing simple harmonic motion will move to and fro in a straight line under the influence of a force. This influential force is called a

## EQUILIBRIUM OF FORCES

CONDITIONS FOR EQUILIBRIUM   A body is said to be in equilibrium if under the action of several forces, it does accelerate or rotate. The sum of the upward forces must be equal to the sum of the downward forces. The sum of the clockwise moment above a point must be equal to the sum

## NEWTON’S LAW OF MOTION

NEWTON’S LAWS OF MOTION Newton’s first law of motion states that everybody continues in its state of rest or of uniform motion in straight line unless it is acted upon by a force. The tendency of a body to remain at rest or, if moving, to continue its motion in a straight line is called

## PROJECTILES AND ITS APPLICATION

MEANING OF PROJECTILE A projectile motion is one that follows a curved or parabolic path .It is due to two independent motions at right angle to each other .These motions are a horizontal constant velocity a vertical free fall due  to gravity Examples of projectile motion are the motion of; a thrown rubber ball re-bouncing

## DERIVATION OF EQUATONS OF LINEAR MOTION

BASIC DEFINITIONS Displacement: This is the distance traveled in a specified direction. It is a vector quantity. Its unit is metres Distance: This is the space or separation between two points. It is a scalar quantity. Its unit is metres Speed: this is the rate of change of distance with time. It is a scalar

## SCALAR AND VECTOR QUANTITIES

CONCEPT OF SCALAR AND VECTOR QUANTITIES Physical quantities are divided into scalar and vector quantities. A scalar is one which has only magnitude (size) e.g. distance, speed, temperature, volume, work, energy, power, mass etc. A vector quantity has both magnitude and direction e.g. force, weight, magnetic flux, electric fields, gravitational   fields etc. VECTOR REPRESENTATION A

## POSITION, DISTANCE AND DISPLACEMENT

POSITION The position of an object in space or on a plane is the point at which the object can be located with reference to a given point (the origin). DISTANCE This is a measure of the separation between two points. It has magnitude but no direction. Hence, it is a scalar quantity   DETERMINATION

## ELECTROMAGNETIC FIELD II

ELECTROMAGNETIC FIELD This is a field representing the joint interaction of electric and magnetic forces.  It is exerted on charged particles.  The force on a charge q moving with velocity v less than the velocity of light is given by F = q (E + v x B) A conductor carrying an electric current when

## ELECTROMAGNETIC FIELD

PATTERNS OF MAGNETIC FIELDS Magnetic field pattern can easily be observed using iron fillings.  The magnetic is put on paper and the iron fillings are sprinkled lightly on the paper around the magnet.  The paper is tapped gently and the iron fillings are found to turn and set to in definite direction. MAGNETIC FIELD AROUND

## MAGNETIC FIELD

MAGNET AND ITS PROPERTIES A magnet is any material that is capable of attracting other pieces of the same material as well as pieces of iron. A substance is said to be ferromagnetic if it is attracted by a magnet. Examples are iron, cobalt, Nickel, and certain alloys. Substances which cannot be attracted by a