Work is defined in physics as the **force that is applied to a body to move it from one point to another** . By applying force, potential energy is released and transferred to that body and resistance is overcome.

For example, lifting a ball off the ground involves doing work since force is applied to an object, it moves from one point to another, and the object undergoes modification through movement.

Therefore, in physics you can only speak of work when there is a force that when applied to a body allows it to move towards the direction of the force.

The working formula is represented as follows:

T = F · d · cosα

Starting from the formula, work is the product of the multiplication of the force by the distance and by the cosine of the angle that results between the direction of the force and the direction that the moving object travels.

However, work ( **null work** ) may not be done when lifting or holding an object for a long time without scrolling as such. For example, when lifting a briefcase horizontally, since the angle between force and displacement is 90 ° and cos 90 ° = 0.

See also the meaning of Physics .

## Work units

**International System of Units:**

Julio or joules (J). 1 J = 10 ^{7} ERG.

**Technical system of units:**

Kilometer or Kilopondimeter (kgm) 1 kgm = 9.8 newtons.

**Cegesimal system of units:**

Eregio: 1 erg = 10 ^{-7} J

**English unit system:**

Foot – poundal (foot – poundal) = 0.0421 joules

## Work in physics examples

**Working with another force or conservative work:** When an archer stretches the bowstring he does work against an elastic bow force.

**Non-conservative work:** an object is forced to move against an opposite force, for example friction between two objects or solid bodies.

**Energy transfer work:** the speed **of energy** is changed during the movement of an object, which can increase or decrease, such as when driving a vehicle.

## Energy

Energy is a **property that all bodies possess** through which they **can transform and modify** their initial state, even bodies at rest possess potential energy.

For example, a lamp may be well placed on a ceiling in a stationary position, however, there is a potential possibility that it will fall for any reason and physical work, i.e. potential energy, will be carried out. And, if potential energy can be transformed into kinetic energy, that results in variation of energy in a moving body.

On the other hand, energy is a property that all bodies possess by which they can transform, as well as modify other bodies, that is, receive or contribute energy. **Through energy, physical, chemical and biological processes are carried out** .

## Power

Power is the **speed with which work is carried out** , that is, it is the energy that is transferred to a body in a unit of time and at a certain speed.