how do you get this equation??
rate of "work done on moving from A to B"
why do you multiply the
force at A and the velocity at A?
the area and velocity are different
at points between A and B
also, is the pressure at any point between
A and B the same?
if yes, what is the pressure at point between A
and B ???
- AAALv 41 decade agoFavorite Answer
Consider the forces at X and Y be Fx and Fy.
Fy is in the opoosite direction of Fx at Fy opposes the motion of fluid.
Let Pressure at X and Y be Px and Py.
Px = Fx / Ax => Fx = PxAx
Py = Fy / Ay => Fy = PyAy, A is the area
As the volume of fluid leaving X is same as the volume of fluid entering Y,
Work done at X
= Fx*x1 (x1 is the displacement caused by force Fx)
= PxAx*x1 = PxV , V is the volume of fluid displaced.
Similarly, work done at Y = -PyV (opposes the motion)
Rate of total work done
= (Px-Py) V / t , t being the time
= (Px-Py) Ax* x1/t
= (Px-Py) Ax*vx, v being the velocity at X.Source(s): /