A non inertial Frame of Refrence is the frame of refrence which is having acceleration a. Example Free Falling elevator
Newtons law are valid in inertial frame of refrence only. We cannot apply them as it is in non inertial frame of refrence as it left out the acceleration of the object because of the frame of refrence.
Let me provide simple example to illustrate this.

This article is about CBSE Class 10 Physics formulas and summary pdf(Free). Having all the formulas in one place is always helpful for the students, Keeping that in mind, We have prepared a physics formula pdf for CBSE Class 10 students.  This physics formula and summary pdf contain the physics formula and outline aimed at

Suppose two charges q1 and q2 are moving with velocities v1 and v2 $respectively. Let r be the distance between the particles at any instant. Now two forces would be acting on each charges at this particular instant
a) Electric Force:- which is given by

We already know about gravitational and electrostatic forces now a question arises that does these forces still hold when we talk about nuclear dimensions as gravitational force between two protons is far too less to hold them and electrostatic force between two protons always a force repulsive in nature . So what hold protons together to form a nucleus.

This article is about Center of mass and torque test for class 11 physics. These are very short answer type and derivation type questions for your exams. Practice them for good marks in your exams. For notes on these topics please click the links given below Center of mass Torque and rotational mechanics Center of mass

This article contains System of particles practice problems with solutions for class 11. In this article I have given numerical problems to solve. You can print this article and practice these problems. You read notes on this chapter before practicing these questions. For them please visit this link Center of mass : System of particles

This page contains physics sample paper class 11 for term 1. You can practice this sample paper after you complete the term one syllabus. This paper includes questions from following chapters. Click respective chapters if you want to get class 11 notes. 1. Units and Measurements 2. Motion in a Straight Line 3. Motion in