Consider the flow of an incompressible newtonian fluid between two parallel plates that are 4 mm apart. if the upper plate moves to the right with u1 = 5 m/s, while the bottom one moves to the left with u2 = 1.5 m/s, what would be the net flow rate at a cross section between the two plates? take the plate width to be 5.5 cm and the distance between the plates to be 4 mm.

Explanation:

We need to find the average velocity of each plate, and .

So substituting,

The net velocity is:

The flow rate =

The flow rate

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.