Work Energy Theorem Examples

Some of the energy imparted to the stone blocks in lifting them during construction of the pyramids remains in the stone earth system and has the potential to do work.

Work energy theorem examples.

The term work is used in everyday life quite frequently and we understand that it s an act of doing something. The work energy theorem explains the reasons behind this physics of no work. For example consider the following figure according to work energy theorem work done by all the forces change in kinetic energy. W g w n w f k f k i.

But physics itself might not agree on this. We know that all the car s kinetic energy is lost to friction. For example when a ball is held above the ground and then dropped the work done by the gravitational force on the ball as it falls is equal to the weight of the ball a force multiplied by the distance to the ground a displacement. For example you are working right now on your grasp of physics by reading this article.

The diagram represents a 155 newton box on a ramp. Therefore the change in the car s kinetic energy is equal to the work done by the frictional force of the car s brakes. A brief overview of energy kinetic energy gravitational potential energy and the work energy theorem for algebra based physics students. In fact the building of the pyramids in ancient egypt is an example of storing energy in a system by doing work on the system.

W n work done by a normal. Equation for the work energy theorem the most commonly encountered form of the theorem is probably wnet 1 2 mv2 1 2 mv02 where v0 and v are the initial and final velocities of the object and m is its mass and wnet is the net work or total work. Therefore we first need to determine the car s kinetic energy at the moment of braking using. Also here the work done is the work done by all forces acting on the body like gravity friction external force etc.

Where w g work done by gravity. Work energy theorem holds for both positive and negative work done if the work done is positive then final ke increases by amount of the work and if work done is negative then final ke decreases by the amount of work done example 1. The work energy theorem is useful however for solving problems in which the net work is done on a particle by external forces is easily computed and in which we are interested in finding the particles speed at certain positions of even more significance is the work energy theorem as a starting point for a broad generalization of the concept.