What is Heisenberg Uncertainty Principle

Heisenberg Uncertainty Principle or indeterminacy principle was given by German scientist Warner Heisenberg according to which position and momentum of an object can not be measured simultaneously. So if we measure the position of some particle more precisely then its momentum is measured less precisely and vice versa.

Heisenberg’s uncertainty principle can be written as follows

NCERT book Solutions class -9 Gravitation (Part 2)

This page contains NCERT book Solutions class -9 Gravitation starting from page 143 at the end of the chapter. I have also been writing the notes for this chapter to learn more about notes you can follow this link and to get the in-text questions solution please follow this link . If you want to get the solutions of first 11 questions follow this link.
For assignment on gravitation follow this link

Question 12
Gravitational force on the surface of the moon is only 1/6 as strong as gravitational force on the earth. What is the weight in newtons of a 10 kg object on the moon and on the earth?

how to solve SHM problems effectively

What is Periodic Motion : In Physics, a motion that is regular and repeating is called Periodic Motion. The time to complete one full motion is called the Time period of the Periodic Motion
What is SHM: A Simple Harmonic Motion is a special case of Periodic motion where a physical quatity varies sinusoidally.In this Periodic motion the restoring force is directly proportional to the displacement. The object oscillates between two position and Motion is sinusoidally in nature.

How to solve Motion Problems of 9th Class

The Motion problem in Class 9 are limited to Straight line motion with either no acceleration or constant acceleration.

This article is given to give the feel of the whole chapters plus the type of questions and ways to tackle them.

This is quite beneficial for anybody studying Motion for class 9.

Complete Study material has been provided at the below link Study Material

First we need to remember these important terms

NCERT book Solutions class -9 Gravitation (Part 1)

This page contains NCERT book Solutions class -9 Gravitation starting from page 143 at the end of the chapter. I have also been writing the notes for this chapter to learn more about notes you can follow this link and to get the in-text questions solution please follow this link

Question 1

How does the force of gravitation between two objects change when the distance between them is reduced to half ?

Answer

According to Universal Law of gravitation , the gravitational force of attrection between any two objects of mass

Computer-based Test Series for Class 9 – Maths, Science, & English

Topics Covered:

Maths:

•Number System

• Polynomials

• Coordinate Geometry, Linear Equations in Two Variables, Introduction to Euclid’s Geometry

• Lines, Angles & Quadrilaterals

• Triangles, Circles and Areas of Parallelograms & Triangles

• Surface Areas & Volumes

NCERT book Solutions class -9 Gravitation (In Text Questions)

These are NCERT solutions for class-9 chapter named Gravitation. Questions in this page are those questions that occur in between the texts at the end of each concept.and I have given the page number so you can find them easily in your book.
Page 134
Question 1
State the Universal law gravitation?
Answer
According to Universal Law of Gravitation every object in universe attracts every other object with a force known as Gravitational force.
It states that

Eligibility Criteria for Appearing in JEE (Advanced) 2015

A candidate can attempt JEE (Advanced) a maximum of two times and that too in consecutive years. Therefore, JEE (Advanced) 2015 should be either the candidate’s FIRST attempt OR the SECOND consecutive attempt.

Criterion 4 – Appearance in Class XII (or equivalent) examination.

The candidate should have appeared for the Class XII (or equivalent) examination for the first time in all the subjects in either 2014 or 2015.

Candidates who appeared for the Class XII (or equivalent) examination in 2014 and wish to re-appear for the same in 2015 (either for improvement or because they failed in one or more subjects), will have to re-appear in all the subjects in 2015.

Those who appeared for the first time in their Class XII (or equivalent) examination in 2013 or earlier are NOT eligible. However, candidates whose Class XII (or equivalent) examination Board results for the academic year 2012-13 were declared after June 2013 are eligible to appear for JEE (Advanced) 2015.