Work Energy Theorem Examples

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.

Work energy theorem examples. A brief overview of energy kinetic energy gravitational potential energy and the work energy theorem for algebra based physics students. W n work done by a normal. 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. For example you are working right now on your grasp of physics by reading this article.

W g w n w f k f k i. 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. 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.

This definition can be extended to rigid bodies by defining the work of the torque and rotational kinetic energy. We apply the work energy theorem. The diagram represents a 155 newton box on a ramp. Also here the work done is the work done by all forces acting on the body like gravity friction external force etc.

But physics itself might not agree on this. The principle of work and kinetic energy also known as the work energy theorem states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. Where w g work done by gravity. 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.

Therefore the change in the car s kinetic energy is equal to the work done by the frictional force of the car s brakes. 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. 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.