Back to Course
Physics NEET: Work, Energy and Power
0% Complete
0/0 Steps

Introduction

The Scalar Product

Notions of Work and Kinetic Energy: The WorkEnergy Theorem

Work

Kinetic Energy

Work done by a Variable Force

The WorkEnergy Theorem for a Variable Force

The Concept of Potential Energy

The Conservation of Mechanical Energy

Potential Energy of a Spring

Various forms of Energy: The Law of Conservation of Energy6Topics

Power

Collisions3Topics
Quizzes
Participants 1
Lesson 11, Topic 4
In Progress
The Equivalence of Mass and Energy
Lesson Progress
0% Complete
Till the end of the nineteenth century, physicists believed that in every physical and chemical process, the mass of an isolated system is conserved. Matter might change its phase, e.g., glacial ice could melt in to gushing stream, but matter is neither created nor destroyed; Albert Einstein (18791955) however, showed that mass and energy are equivalent and related by the relation
E = mc^{2} ……………………………………………………………………….(20)
where c, the speed of light in vacuum is approximately 3 × 10^{8 }m s^{1}. Thus, a staggering amount of energy is associated with a mere kilogram of matter
E = 1 ×(3 × 10^{8})^{2 }J = 9 × 10^{16 }J.
This is equivalent to the annual electrical output of a large (3000 MW) power generating station.