In an annulus formed between a rod of radius r0 and a concentric tube with radius r1, the rod is rotated with an angular velocity ω while the tube is stationary. the upstream and downstream pressures are the same. find the expression for the velocity components of the fluid contained within the annulus.

The correct answer is they are attracted to each other.

Explanation:

There are 2 poles of a magnet: North and South pole.

When two same poles come closer to each other, they are repelled by each other. North and North pole will repel each other and likewise with south pole.

When two different poles come closer to each other, they are attracted to each other. North and South pole with attract each other.

We are asked the interaction between two opposite poles, so the correct answer is that they are attracted to each other.