ENERGY AND WORKEnergy, Work, and PowerCP-05 Page 4Rev. 0WorkWork is commonly thought of as any activity requiring exertion. However, the definition inphysics is much more specific. Workis done by a force acting on a moving object if the objecthas some component of motion in the direction of the force. Work can be done BY a person,a machine, or an object by applying a force and causing something to move. More specifically,work is done by a force acting on a moving object if the object has some component of motionin the direction of the force. Work can be done ON an object by applying a force that causesit to move. For example, if you push on a box (apply a force) and it moves three feet, work hasbeen performed BY you to the box, while work has been performed ON the box. If you pushon the box and it does not move, then work, by our definition, has not been accomplished.Work can be defined mathematically by Equation 5-3.W = F x d(5-3)where:W=work done in ft-lbfF=force applied to the object in lbfd=distance the object is moved (in ft.) with the force appliedExample:You push a large box for three minutes. During that time, you exert a constantforce of 200 lbf to the box, but it does not move. How much work has beenaccomplished?W =F x dW=200 lbf x 0 ftW=0 ft-lbf work doneRemember that if no movement is achieved, no work has been accomplished. Even if you feelfatigued, no work has been done. Work can be thought of as what has been accomplished. Ifnothing is accomplished, then no work has been done.Example:You push the same box as mentioned above. You apply a horizontal force of200 lbf to the box, and the box moves five feet horizontally. How much workhave you done?W =F x dW=200 lbf x 5 ftW=1000 ft-lbfIn this case, work can be described as work done by the person pushing the box or workperformed on the box. In either case, the amount of work is the same.