Skip to main content

Elastic and Inelastic Collisions

Understanding conservation of energy using collision of elastic and inelastic bodies

Consider the impact between two bodies which move with different velocities along the same straight line. It is assumed that the point of impact lies on the line joining the centers of gravity of the two bodies. The behavior of these colliding bodies during the complete period of impact will depend upon the properties of the materials of which they are made. The material of the two bodies may be perfectly elastic or perfectly inelastic.

The bodies which rebound after impact are called elastic bodies and the bodies which does not rebound at all after its impact are called inelastic bodies. The impact between two lead spheres or two clay spheres is approximately an inelastic impact.

The loss of kinetic energy (EL) during impact of inelastic bodies is given by

Loss of Kinetic Energy for elastic bodies

where

m1 = Mass of the first body,
m2 = Mass of the second body,
u and u2 = Velocities of the first and second bodies respectively.

The loss of kinetic energy (EL) during impact of elastic bodies is given by

Loss of Kinetic Energy for inelastic bodies

where
e = Coefficient of restitution.

Coefficient of restitution

Notes:

1. The relative velocity of two bodies after impact is always less than the relative velocity before impact.

2. The value of e=0, for perfectly inelastic bodies and e=1, for perfectly elastic bodies. In case the bodies are neither perfectly inelastic nor perfectly elastic, then the value of e lies between zero and one.

Comments

Popular posts from this blog

Are Engineers Favourite Among Girls?

What do girls think about men who are engineers and what type of engineers are most favourite among girls? A survey was conducted by a team of aboutmech with members chosen from different countries. Each team member carried out a neutral survey in his/ her country to evaluate what females think about most of the engineers from different engineering branches. An overview of different questions asked in survey is given below:

Question: Which male engineers do you find more attractive as a husband?
Almost 50% women voted for mechanical engineers to be the most attractive husbands among other engineers. So mechanical engineers are most favourite among girls as a husband. They find them more trustworthy, intelligent, and creative. A married women from California said, “If your husband is a mechanical engineer, he will help you in everyday tasks. Because mechanical engineers are good team players and they have creative ideas about everything.”

Best CV Format for Mechanical Engineers

Fifty percent engineers fail to grab a dream job because of basic faults in their CVs/ Resume. This article tells you about best CV format for mechanical engineers and how you are supposed to design your CV when applying for jobs. You CV is your first impression on future employer. He/ she does not know you. Your CV is the only representation of your personality. He/ she may select or reject you after first glance on your resume. 
I have experienced shortlisting and interviewing candidates for different jobs. I was astonished to learn that most of the candidates simply copy paste each others CVs without any changes at all. These types of CVs are rejected immediately. I am not trying to tell you that you should avoid copying, rather i ma telling you to refrain from giving your CV to your friends.
An ideal CV consists of following portions:
Name/ Address of the applicantObjectiveEducation RecordEmployment HistoryProfessional SkillsAwards & AchievementsCo-Curricular Activities/ Inter…

Engineering Mechanics - Introduction

The Engineering Mechanics is that branch of Engineering-science which deals with the principles of mechanics along with their applications to engineering problems. It is sub-divided into the following two main groups:

(a) Statics, and (b) Dynamics

The Statics is that branch of Engineering Mechanics which deals with the forces and their effects, while acting upon the bodies at rest.

The Dynamics is that branch of Engineering Mechanics which deals with the forces and their effects, while acting upon the bodies in motion. It is further sub-divided into the following two branches:

(i) Kinetics, and (ii) Kinematics

The Kinetics is that branch of Dynamics, which deals with the bodies in motion due to the application of forces.

The Kinematics is that branch of Dynamics which deals with the bodies in motion without taking into account the forces which are responsible for the motion.