NEWTON'S LAWS OF MOTION ~ GENERAL STUDIES 4 U|FOR ALL COMPETITIVE EXAMS

NEWTON'S LAWS OF MOTION

NEWTON'S FIRST LAW

It states that every body continues in its state of rest or in uniform motion in a straight line, unless it is compelled by an external force to change that state.

First law is also called law of Galileo or law of inertia.

APPLICATIONS

Athlete runs some distance, before taking a long jump.

A ball thrown upwards in a train moving with uniform velocity returns to the hand of thrower.

The mud from the wheels of a moving vehicle flies-off tangentially.

When we shake the branch of a mango tree, the mangoes fall down.

A man jumping from a moving train may fall down.

If a cloth placed under a book is given a sudden pull, it comes out without disturbing the book.

When a horse suddenly starts moving, the rider falls backward.

We hit a carpet with a stick to remove the dust.

NEWTON'S SECOND LAW

According to it, the force acting on an object is directly proportional to the product of the mass of the object and the acceleration produced on it.

or F∝m✕a⇒F=kma

value of k is 1 in SI system ⇒F=ma It's SI unit is newton.

Newton's second law gives the magnitude of force.

Newton's first law is contained in the second law.

APPLICATIONS

China wares are wrapped in straw or paper before packing.

A person falling on pucca floor (or frozen ice) is likely to receive more injuries than one falling on kuccha floor (loose earth).

While catching a ball, a cricket player lowers his hands to save himself from getting hurt.

Bogies of the trains are provided with buffers to avoid severe jerks during shunting of trains.

NEWTON'S THIRD LAW

According to this law, to every action there is an equal and opposite reaction.

APPLICATIONS

In order to walk,we press the ground in backward direction with our feet.As a result, the earth on other hand pushes us in forward direction.

It is difficult to drive a nail into a wooden block without holding the block.A jet plane moves on the principle of Newton's third law of motion.As exhaust gases come out from the nozzle at a greater speed, the reaction of the same moves the plane forwards.