What is Work?

In classic physics terms, you do occupational on an object when friend exert a pressure on the object bring about it to move some distance. The quantity of occupational you actually do may have small relationship come the quantity of initiative you apply.

For example, if you push on a vehicle stuck in a snow drift, you might exert a lot of force (and effort) but if the car does no budge, you have actually not done any type of work! In bespeak for occupational to be done on an object, the thing must move some street as a result of the pressure you apply. There are also constraints on the pressure you apply. Only force exerted in the very same direction as the movement of the object an outcome in work. You may think that you perform a lot of work if you bring an arm full of books from house to school. In reality you execute no occupational at all! In transferring the stack of books, girlfriend exert one upward force to hold the publications so they don"t autumn to the ground. There is no movement associated with this force. Together you walk, the activity of the books is horizontal not vertical. Due to the fact that the force applied to the books is vertical, and the movement is horizontal, you do not do any work top top the books.

Work is a deliver of power so job-related is excellent on things when you transfer power to that object. The amount of occupational done on an object depends top top the quantity of force exerted top top the object and the amount of street the object moves.

You are watching: Exert 100 j in 50 s and your power output is

Work = force x Distance

According to Newton"s second Law the Motion, the net force on an object is dependent on the fixed of the object, and its acceleration throughout the movement.

Force = mass x Acceleration

The usual unit of pressure is the Newton (N). One Newton is the force required to accelerate one kilogram that mass in ~ 1 meter per 2nd per second.

1 N = 1kg m/s2

The lot of work-related done to press a 10,000 N vehicle a distance of 10 meters jajalger2018.orgld certainly be

10,000 N x 10 m = 100,000 N m or 100,000 J

The Newton-meters room termed joules (J). The joule is called after James Prescott Joule (1818-1889) who first calculated the lot of electric work needed to create a unit that heat. In his experiments, Joule discovered that the very same amount of warm was developed by the exact same amount that either electric or mechanical occupational ("the mechanical tantamount of heat").

Learn an ext about work-related here.

What is Energy?

On march 10, 2005 sounding prefer an approaching locomotive, a tornado dropped out of billowing black clouds on the brand-new Zealand town of Greymouth. The winds hurled a truck into a lagoon, snapped strength poles in half, roofs sailed through the air and also buildings were destroyed (go right here to view a video clip of this disaster).

Although wind is just moving air, it possesses energy. When the wind moves the sheet on a tree or picks up and also hurls a truck, it has actually caused a change in the place of the object. Thus it has actually done work. A measure of the ability to do job-related or cause readjust is called energy. Any type of time an item does work on an additional object, few of the energy of the working object is moved to that object increasing its power state. Favor work, the units of power are joules.

Energy is the quantity of work a physical device is capable of performing so energy can be identified as the which transforms the position, physical composition or temperature of an object. There room two category of energy, kinetic energy and potential energy. The difference between them is whether the energy is being transferred (kinetic) or save (potential). They are interconvertible.

Kinetic power is the energy of movement (the activity of waves, electrons, atoms, molecules) if potential energy is stored energy or energy of place that has the potential to do occupational (follow the kinetic and potential energy links for a an ext in depth discussion). The kinetic energy of an object is dependent both the massive of the object and also its velocity.

K.E. = 1/2 m v2

Thus a 3,000 lb vehicle moving at 50 mph will certainly transfer an ext kinetic power than a 2,000 lb automobile moving in ~ the same rate. Power can be stored in things by lifting the up. The amount of potential power jajalger2018.orgld be

P.E. = mgh

where m is the massive of the object; h is the elevation of the object, and also g is the force of gravity exhilaration on the object.

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This computer animation shows how energy converts in between kinetic and also potential energy.

Animation courtesy of: http://www.bsharp.org/physics/stuff/swings.html

View just how kinetic and potential energy are interrelated utilizing a roller coaster demonstration.


A waterfall possesses both potential and kinetic energy. The water at the height of the falls possesses potential energy. As the water flows over the sheet of the falls, its energy is readjusted into kinetic energy.