Work Done And Kinetic Energy Formula

Kinetic energy is a form of energy that an object or a particle has by reason of its motion.

Work done and kinetic energy formula. This definition can be extended to rigid bodies by defining the work of the torque and rotational kinetic energy. Where ke stands for kinetic energy. In other words the change in kinetic energy of a body is equal to the amount of work done on that body. By now we have started to sense that work and kinetic energy are closely related.

It needs to be emphasized that the work energy equation only applies to work done by the net force in a mechanical system the work done by just any old force may or may not show up as kinetic energy but the work done by the net force always shows up as kinetic energy. This version of the work energy equation was derived for one dimensional motion and is valid. Note that the work in this equation is the work done by the net force rather than the work done by an individual force. The kinetic energy of an object is denoted by ke and its si unit is joules j.

The unit for kinetic energy is the same unit for work the joule. Kinetic energy is a scalar. We apply some force in the opposite direction now the velocity becomes less than v or in other words the body loses kinetic energy so where has that energy gone. The result based on newton s laws that the net work done on an object is equal to its change in kinetic energy kinetic energy.

Now suppose a ball is moving with velocity v. This is known as work done by force. Ke 1 2 kg v 2. So we can define work done by a force as energy given or taken from the system of objects.

Where v stands for an object s velocity. Thus we define the kinetic energy as the capacity of an object to do work by virtue of its motion. The work done on an object by a net force equals the change in kinetic energy of the object. The units are the same as for work i e.

Relation bewteen ke and w. There is a strong connection between work and energy in a sense that when there is a net force doing work on an object the object s kinetic energy will change by an amount equal to the work done. The energy an object has by reason of its motion equal to latex frac 1 2 text mv 2 latex for the translational i e non rotational motion of an object of mass m moving at speed v. Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass.

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. Very important fine print. The work energy principle states that an increase in the kinetic energy of a rigid body is caused by an equal amount of positive work done on the body by the resultant force acting on that body. If work which transfers energy is done on an object by applying a net force the object speeds up and thereby gains kinetic energy.

Conversely a decrease in kinetic energy is caused by an equal amount of negative work done by the resultant force.