When you ride a roller coaster, you hear a slow click-clack as the car is pulled to the top of the hill. Soon its potential energy will quickly turn into kinetic energy as the car races back down. A force is used to push the roller coaster car a distance and give it all the energy it needs to roll through the rest of the track. We call that force over a distance work.
Watch this animation to find out more about work and how it can change the mechanical energy of an object. As you watch the segment, you might want to check the definitions of specific terms. In addition to the glossary words listed above, displacement will be described.
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Energy moves from system to system, place to place, all the time. And as it moves it interacts with all of the different things around it. One of the ways we can understand these interactions is by measuring the “work done” by that energy within a system.
Energy transferred through a force onto an object has the potential to make that object move. When it does, and that object moves a distance, we measure the overall effect of the energy applied as “work done.”
Work done on a system can be positive when the energy moves the object in the same direction as the force is going.
But when force is applied in the opposite direction of the movement, the work done is negative. Energy is taken away from the system.
And work can also be measured as zero if energy is applied to a system, but there isn’t enough or the direction of the forces are such that there is no displacement and therefore no work done.
Work is a measurement of how energy transfers through a given system with all of its different variables. And if we understand, and can even predict, how energy enters a system and what it will do in that system, we can harness it to do as we please.
Because energy is what makes the world go, but work is what makes it go round.
In the space below write a definition of work. Describe when work is positive, negative, and zero.