Work Done in lifting mass through Non viscous Medium

To lift a body of certain mass from a certain position to a new position in a liquid, we need to do some work and after the work done, this work done will be stored in the form of potential energy.If the body is in air, it is approximately treated like vacuum and upthrust is ignored.

If the body is in a liquid medium, to lift it from the place, we need to do work against gravitational force. The liquid applies resultant upward force and it is also called as buoyant force.

Here this force is acts in the upward direction and it shall help in lifting the body.

The resultant force acting on the body is the difference between gravitational force and up thrust. This resultant force acts in downward direction as gravitational force is dominated one than buoyant force. As it is acting in the upward .direction, it shall be treated as negative force.

We have ignored viscous force as the medium is assumed to be non viscous.

We can measure the effective acceleration of the system by simplifying the equation.It is shown in detail in the video presented below.

By substituting this effective acceleration value in the potential energy format, we can measure the work done in lifting the body through a liquid as shown below in the video.