]]>
LearnNext
Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

clear

Motion of Centre of Mass

13,031 Views
Have a doubt? Clear it now.
live_help Have a doubt, Ask our Expert Ask Now
format_list_bulleted Take this Lesson Test Start Test

Motion of Centre of Mass - Lesson Summary

Let us consider a system of n particles with its total mass constant with respect to time. Consider particle ‘i’ from the system. In the graph, its position is marked by vector ri and the centre of mass of the given system of particles is denoted as ‘R’.

 
This means that: The motion of the centre of mass of a system of particles is independent of the internal forces. The centre of mass moves as if the whole mass of the system is concentrated at it and the external force is acting on it.

The total momentum of the system of particles is equal to the product of the total mass of the system and the velocity of the centre of mass. We have F ext = d p/dt.  This is Newton’s Second Law of Motion applicable to the system of particles.

If the external force acting on the system of particles is zero, then F ext  = 0 and hence p is a constant.
This is the Law of Conservation of Momentum applicable to a system of particles: “If the total external force acting on a system of particles is zero, then the linear momentum of the system is constant”.

 A rigid body may have both translational and rotational motion. In such cases, it is usually convenient to work with a reference frame that is attached to the centre of mass of the system of particles.                     

Comments(0)

Feel the LearnNext Experience on App

Download app, watch sample animated video lessons and get a free trial.

Desktop Download Now
Tablet
Mobile
Try LearnNext at home

Get a free home demo. Book an appointment now!

GET DEMO AT HOME