Work Is A Transfer Of

Work

Definition Of Work

Work is the transfer of free energy .

In physics we say that work is done on an object when yous transfer energy to that object.

If you put energy into an object, then you do work on that object (mass).

If a offset object is the amanuensis that gives free energy to a second object, then the starting time object does work on the second object. The energy goes from the get-go object into the second object.

At start we volition say that if an object is standing however, and you become it moving, then you accept put energy into that object. The object has kinetic free energy every bit a result of your work. Yous pushed information technology through a displacement, you did work on the object.

Person swinging golf club For example, a golfer uses a club and gets a stationary golf ball moving when he or she hits the ball. The club does work on the golf brawl every bit it strikes the ball. Free energy leaves the club and enters the ball. This is a transfer of energy. Thus, we say that the gild did piece of work on the ball.

And, before the brawl was struck, the golfer did work on the club. The society was initially standing still, and the golfer got it moving when he or she swung the club.

Transfer Of Energy

Then, the golfer does work on the club, transferring energy into the club, making it move. The club does work on the ball, transferring energy into the ball, getting it moving.

Formula For Work

In almost all cases considered when studying mechanical forms of energy, when work is done on an object a strength is practical to the object , and the object is displaced while this force is acting upon it. That is, the object moves as a result of a force being placed on information technology.

In the previous golf example the gild places a force on the ball, and this forcefulness acts on the ball over the short altitude through which the club and the ball are in contact every bit the ball is being hit. Energy is transferred equally the strength acts over this deportation.

The amount of work is calculated past multiplying the forcefulness times the displacement. That formula looks similar this:

A word almost dot products: On the right of the equal sign is the dot product of the force vector times the displacement vector. If the object is displaced in the same management every bit the strength is pushing, then this dot production becomes a simple multiplication of the size of the strength times the size of the displacement.

At get-go we will consider only forces that are aimed in the same direction as the deportation. Then, we will be using the simple multiplication mentioned above. For instance, nosotros volition imagine an object being pushed horizontally to the correct, and the object will be moving horizontally to the right as a result of this applied force.

Force Is Parallel To Displacement

Beneath is an animation that shows just that. The force vector is fatigued in blue. It is pushing the object to the right. This force is practical over a displacement. The displacement vector is shown in ruby. The yellow object (mass) starts out standing all the same. While the force is acting on the object the object picks upwardly speed, that is, it accelerates. When the force quits acting, the object quits picking up speed; that is, information technology quits accelerating.

A medium strength acts on the object (mass) over a medium displacement:

Strength = 0 Displacement = 0 Work = 0
Velocity = 0 Acceleration = 0
Notes

Paused

Notice that in the above animation the object picks up speed while the force is acting upon it. This picking upwardly of speed means that the object is gaining more than and more than energy (kinetic free energy) as the force is interim on it. While the strength is interim upon the object, free energy is being transferred to the object. Therefore work is existence done on the object. Whatsoever we might imagine is providing the strength is the agent that is doing work on the object. In our above discussion the force could be practical by the golf club, and the object in the animation represents the golf brawl. This, of course, would need to exist idea of as in slow motion!

Now, since piece of work is calculated as the product of force times displacement, many different combinations of forces and displacements could yield the same work, or the same free energy transfer. Using units of Joules (J) for work, Newtons (N) for force, and meters (m) for displacement:

West = (F)(d)

12 J = (1N)(12m)

12 J = (2N)(6m)

12 J = (3N)(4m)

So, pocket-sized forces acting over large displacements can do the same work equally large forces acting over pocket-size displacements.

For example, compared to the to a higher place animation, the post-obit animation has a larger force that acts over a shorter displacement, withal the same amount of piece of work is ultimately washed.

A large strength acts on the object (mass) over a small displacement:

Force = 0 Displacement = 0 Work = 0
Velocity = 0 Acceleration = 0
Notes

Paused

And in this side by side animation, compared to the kickoff, a smaller force and a larger deportation is demonstrated. Again, the aforementioned amount of work is done. The same corporeality of energy is transferred.

A small strength acts on the object (mass) over a large displacement:

Force = 0 Deportation = 0 Work = 0
Velocity = 0 Acceleration = 0
Notes

Paused

Later, we will encounter what happens when a force is applied at an angle to the displacement. For a while, though, we will consider only forces in the same direction every bit the displacement.

Sample Calculation

How much work is done if a force of 20 N is used to readapt an object 3 m?

Westward = F · d	Formula for piece of work.
W = (20 N)(3 m)	Plug in values for force and displacement.
West = 60 N-one thousand	Work equals 60 units of energy transferred. Looks like the unit for energy transferred, and thus, the unit for free energy, is Newton-meter. However, it is usually non done that way.
Due west = 60 Joules	Free energy units are called Joules, ane Joule is equal to 1 Newton-meter. A Joule is the MKS metric unit for free energy.
Westward = 60 J	Joule is abbreviated J.