Force and work - The concept of force and work is explained.

Force and work

Work as defined in physics is quite different from the everyday meaning. In physics, we say that work is always the production of motion against opposition. You cannot do work in the physical sense unless, by exerting a force, you overcome resistance, when you walk upstairs you are doing work because you are lifting your weight against the resistance of gravity.

How much work you do always depends upon the weight you lift and the distance through which you lift it. If you pull a heavy load along the ground you are doing work because you are moving a weight against the resistance due to friction. Here, again, the amount of work you do depends upon the weight of the load you are pulling and the distance over which you pull it. Work always the product of force time’s distance.

                             Work = force × distance

Since work always involves motion, it follows that if there is no motion there is no work. Lifting a heavy weight requires work; holding that weight still does not require work. The unit of work which we shall consider here is the foot-pound. It is equal to a pound of force moving through a distance of one foot. 

If you weigh 160 pounds and walk up a hill to a height of 100 feet, you have done 160 × 100 or 16000-foot pounds of work because you have moved your weight against the force of gravity for a distance of 100 feet. If you walk the same distance on level ground, the work the force of gravity to such an extent, but is overcoming primarily a certain amount of frictional resistance.
Force and work - The concept of force and work is explained. Force and work - The concept of force and work is explained. Reviewed by knowledge people creators on March 29, 2019 Rating: 5
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