Work , Power & Energy ( Introduction )

 Introduction :

    The terms work , energy and power are frequently used in everyday language. 

For example , A woman carrying water from a well to her house is said to be working. In a drought affected region she may be required to carry it over large distances. If , she can do so , she is said to have a large stamina or energy.

Energy is thus the capacity to do work. The term power is usually associated with speed. 

In physics we shall define these terms very precisely.

Work :

 work is related to force and the displacement over which it acts. Consider a constant force F acting on an object of mass m. The object undergoes a displacement d in the positive 

x - direction as shown in Fig.

The work done by the force can be defined as 

" the product of magnitude of displacement and component of force along the displacement ".

work is a scalar quantity. The S.I unit of work is joule( J ) and C.G.S  unit of work is erg. 

work done can be calculated by following three ways.

1. work done by area under 

force - displacement curve.

2. work done by a constant force.

3. work done by a variable force.

work done by a constant force :

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https://youtu.be/_Dq2jB28Lfc

https://youtu.be/eGmMrJ8Qywo