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All Work and no Play
Work, work, work. You might head off to your job one day, sit at a computer, and type away at the keys. That's all we do here. Is that work? To a physicist, only parts of it are. Work is a force that is applied to an object and then multiplied by the movement of an object.
Sitting and looking at a computer screen is not work. Tapping on the keyboard and making the keys move is work. Your fingers are moving and applying a force. Driving to your job is not work because you just sit, but the effort of your car engine to move the car is work. You have to move something, anything, even an atom, to qualify as work. Imagine that you are holding a brick above the ground. Your arm is straight out in front of you and it's pretty tough to hold. Slowly, your arm gets tired, the brick feels heavier and heavier, and you stop to let your arm rest. Even though you put forth a lot of effort to hold the brick up, did you do any work? Nope. The brick didn't move. No work was done if no movement happened. If you lifted the brick again after your arm had rested, that would be work. 
Transfer of EnergyWork is one of the things that happens when force is transferred from one object to another. We've already talked about moving objects. What else? Work is also linked to the expansion and compression of gases. When an object heats up, heat is released, and warms the air around it. When the gas expands because of the additional energy and starts things moving, work is being applied to the system.Measuring WorkWhen scientists measure the work of gases, they look at the system at the beginning and the end of the project. They look at the initial and final states. Sometimes they take measurements while things are happening. Those measurements are of the intermediate states. When everything is said and done, they total up all the measurements to figure the total work done.To figure out the total work a system has done they use the formula W = P (delta)V. W stands for work, P is the pressure of the system (for gases), and delta V is the change in volume for the system. 
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