Is there any video I can use to visualise why velocities change in moving rotating reference frames? Suppose we have a car A moving along a straight path and another car B moving in a circular path. I know from the formula I have studied that the relative velocity of A as observed by B will not simply be

$v_b-v_a$

But I still can not get a 'feel' of why this is so. It just seems so natural to think that the above expression should be the expression for relative velocity in ANY frame regardless of whether it rotates or not, after all, relative velocity is the velocity of one object with respect to other and it seems like a simple difference of velocities should do the trick!
 A: I'll give you an idea. Suppose you're sitting on a turntable and your friend is rotating it. Suppose you are at the centre of the turntable. You will see your friend moving right? You are in a rotating frame and both of you are not moving in the ground frame so the difference in the velocities is zero but you still see him moving.

Hope it gives you an intuition.
A: Here's a simple example that may help you understand relative velocity involving rotating frame of reference.
Suppose, you and your friend are sitting at diametrically opposite ends of a rotating turntable.

Lets take an instant where your friend's velocity is the vector $v$ wrt an stationary observer sitting just behind the table. Thus, your velocity must be $-v$ in this stationary frame of reference.
By the formula you mention, the relative velocity of your friend wrt your frame of reference then should have been

$v-(-v) = 2v$.

But you will always see your friend at the opposite end of the table stationary, not moving an inch. You see the surrounding is in motion, but not your friend, implying the velocity of your friend relative to you is always 0.
The formula you've mentioned is just a special case of relativity where two people have their velocities always along the same straight line wrt a stationary observer.
