A piston-cylinder device containing a fluid is fitted with a paddle wheel stirring device operated by the fall of an external weight of mass 51kg. As the mass drops by a height of 5.6m, the paddle wheel makes 10100 revolutions. Meanwhile the free moving piston (frictionless and weightless) of 0.51m diameter moves out by a distance of 0.71m. Determine the net work for the system if atmospheric pressure is 101 kPa.

The value is

Explanation:

From the question we are told that

The mass of the external weight is

The height through which the mass drops is

     The  number of revolution made is  

    The  diameter of the free moving piston is    

     The distance moved by the free moving piston is  

     The  atmospheric pressure is  

Generally the workdone by the  external weight is mathematically represented as

=    

=    

Generally the workdone by the free moving piston  is mathematically represented as  

Here   A is the cross-sectional area with value  

So

=>      

So

   The net workdone is mathematically evaluated as

The negative sign shows that it is acting in opposite direction to

So

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.