Physics Work Energy Theorem Examples

This physics video tutorial provides a basic introduction into the work energy theorem also known as the work energy principle.

Physics work energy theorem examples.

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. In physics work is the process of energy transfer to the motion of an object via application of a force. W g w n w f k f k i. The relationship between work and kinetic energy of the object is called the work energy theorem.

We apply the work energy theorem. For example consider the following figure according to work energy theorem work done by all the forces change in kinetic energy. 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. We know that all the car s kinetic energy is lost to friction.

7 2 5 w n e t 1 2 m v 2 1 2 m v 0 2. General derivation of the work energy theorem for a particle. Therefore we first need to determine the car s kinetic energy at the moment of braking using. Examples of forces that have potential energies are gravity and spring forces.

The quantity 1 2mv2 1 2 m v 2 in the work energy theorem is defined to be the translational kinetic energy ke of a mass m moving at a speed v. This definition can be extended to rigid bodies by defining the work of the torque and rotational kinetic energy. When you are walking or running your body is exhibiting kinetic energy. Also here the work done is the work done by all forces acting on the body like gravity friction external force etc.

W n work done by a normal. Where w g work done by gravity. It states that the net work done on the system is equal to the change in kinetic energy of the system w net delta k. Running water has kinetic energy and it is used to run water mills.

Therefore the change in the car s kinetic energy is equal to the work done by the frictional force of the car s brakes. Work energy theorem the net work on a system equals the change in the quantity 1 2 m v 2. The quantity 1 2 m v 2 in the work energy theorem is defined to be the translational kinetic energy ke of a mass m moving at a speed v. 5 work energy theorem.

Here are some kinetic energy examples. Translational kinetic energy is distinct from rotational kinetic energy which is considered later.