Physics - Gravitation

Description

Description

Early in our lives, we become aware of the tendency of all material objects to be attracted towards the earth. Anything thrown up falls down towards the earth, going uphill is lot more tiring than going downhill, raindrops from the clouds above fall towards the earth and there are many other such

phenomena. Historically it was the Italian Physicist Galileo (1564-1642) who recognised the fact that all bodies, irrespective of their masses, are accelerated towards the earth with a constant acceleration. It is said that he made a public demonstration of this fact. To find the truth, he certainly did experiments with bodies rolling down inclined planes and arrived at a value of the acceleration due to gravity which is close to the more accurate value obtained later.

A seemingly unrelated phenomenon, observation of stars, planets and their motion has been the subject of attention in many countries since the earliest of times. Observations since early times recognised stars which appeared in the sky with positions unchanged year after year. The more interesting objects are the planets which seem to have regular motions against the background of stars. The earliest recorded model for planetary motions proposed by Ptolemy about 2000 years ago was a ‘geocentric’ model in which all celestial objects,

stars, the sun and the planets, all revolved around the earth. The only motion that was thought to be possible for celestial objects was motion in a circle. Complicated schemes of motion were put forward by Ptolemy in order to describe the observed motion of the planets. The planets were described as moving in circles with the centre of the circles themselves moving in larger circles. Similar theories were also advanced by Indian

astronomers some 400 years later. However a more elegant model in which the Sun was the centre around which the planets revolved – the ‘heliocentric’ model – was already mentioned by Aryabhatta (5th century A.D.) in his treatise. A thousand years later, a Polish monk named Nicolas

Copernicus (1473-1543) proposed a definitive model in which the planets moved in circles around a fixed central sun. His theory was discredited by the church, but notable amongst its supporters was Galileo who had to face prosecution from the state for his beliefs. It was around the same time as Galileo, a nobleman called Tycho Brahe (1546-1601) hailing from Denmark, spent his entire lifetime recording observations of the planets with the naked eye. His compiled data were analysed later by his assistant Johannes Kepler (1571- 1640). He could extract from the data three elegant laws that now go by the name of Kepler’s laws. These laws were known to Newton and enabled him to make a great scientific leap in proposing his universal law of gravitation.

Course Content

Newton's law of Gravitation

Variation of 'g' due to altitude

Variation of 'g' due to depth

Variation of 'g' due to latitude

Kepler's laws

Gravitational and Inertial mass

Orbital / Critical velocity of satellite

Periodic time of satellite

Gravitational potential energy

Binding Energy of a satellite

Escape Velocity of a satellite

Projection of a Satellite

Communication Satellite

Weightlessness

What You Will Learn!

• Learners will be able to understand Concept of gravitational force between two bodies and its conservative nature.
• Learners will be able to understand the Concept of variation of acceleration due to gravity with height and depth.
• To make them understand principle of launching satellite, escape and orbital velocity.
• Learner will able to Calculate potential and potential energy.
• Factors on which the escape speed of a body depends, Principle of launching a satellite and terms related to its motion.
• They will understand the effects of weightlessness.
• understand that if gravity is the only force acting on an object, the sum of kinetic energy and gravitational energy is constant
• understand that increases in kinetic energy are balanced by decreases in gravitational energy, and vice versa
• Understand that there are various forms of potential energy, all of which depend on the position of an object rather than on its motion.

Who Should Attend!

• Physics enthusiast.
• Beginners in Physics .
• IIT-JEE & NEET aspirants

TAKE THIS COURSE