VIDHYAKSHETHRA

Friction  is a force that acts to stop the movement of two touching things. Two kinds of friction are static and kinetic. Static friction is when the friction is strong enough to stop movement between two objects. Kinetic friction is used when the frictional force is not strong enough to stop all motion. Static friction opposes impending motion , i.e. the motion that would take place under the applied force, if friction were absent and is denoted by f s . It is found experimentally that the limiting value of static friction is independent of the area of contact and varies with the normal force(N) approximately as ( f s )max = µ s N . If applied force exceeds (f s )max the body begins to slide on the surface. Kinetic Friction is the frictional force that opposes relative motion between surfaces in contact. It is also called sliding friction and is denoted by f k . Kinetic friction, like static friction, is found to be independent of the area of...

Newton's Third Law of Motion According to Newtonian mechanics, every force in nature exist in pairs. There will be always an equal and opposite force between two bodies. These forces occur at the same instant. These two forces are equal and opposite and act on separate bodies.  Newton's third law states that, to every action, there is an equal and opposite reaction. For example if we let the air out from a balloon, the escaping air will exert a force on the ground (action) and the ground in turn exerts an equal and opposite reaction on the balloon and hence the balloon goes up.  Newton's third law can be expressed mathematically as F 12 = -F 21 . Here  F 12 is the force exerted by body 1 on body 2 (action) and is force exerted by body 2 on body 1 (reaction). The negative sign shows that both forces are opposite to each other.  Law of conservation of momentum It is a consequence of the Newton's second and third laws of motion. It states that the...

Newton's Second Law of Motion :  The second law of motion refers to the general situation when there is a net external force acting on the body. It states that The rate of change of momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts. It means that the linear momentum will change faster when a bigger force is applied. Momentum  can be defined as "mass in motion." All objects have mass; so if an object is moving, then it has momentum - it has its mass in motion. The amount of momentum that an object has is dependent upon two variables: how much stuff is moving and how fast the stuff is moving. Momentum depends upon the variables mass and velocity. In terms of an equation, the momentum of an object is equal to the mass of the object times the velocity of the object. Momentum (p) = Mass(m) x Velocity(v) DERIVATION OF SECOND LAW OF MOTION  Consider a body of mass ‘m’ moving with veloci...