Friday, 21 July 2017

CBSE Class 8 - General Science - Unit Test Paper - 1 (2017-18) (#cbsePapers)

CBSE Class 8 - General Science  - Unit Test Paper - 1 (2017-18) (#cbsePapers)

CBSE Class 8 - General Science  - Unit Test Paper - 1 (2017-18) 

Chapters covered:

1. Microorganisms
2. Metals and Non-Metals
3. Force and Pressure

Wednesday, 19 July 2017

CBSE Class 11 - Physics - Gravitation - Kepler's Laws (#cbseNotes)

Kepler's Laws

Class 11 - Physics - Gravitation 
CBSE Class 11 - Physics - Gravitation - Kepler's Laws (#cbseNotes)


Kepler's Laws


There has always been a great interest in the motion of planets. Part of the reason is that some people believe that it changed the course of science and laid foundation to Newtonian Laws. By 16th century, a lot of data on the motion of planets had been collected by many astronomers. Based on that data Johannes Kepler, after a life time study, worked out three empirical laws which govern the motion of planets and are known as Kepler's laws of planetary motion.

The laws for planets orbiting the sun, they hold equally well for satellites, either natural or artificial, orbiting Earth or any other massive central body.

The three laws are:

The law of orbits
Law of areas
Law of periods