Question
Two particles A and B are connected by a rigid rod AB as shown in figure. The rod slides along perpendicular rails. Where the rod subtends an angle a = 30° with the horizontal, the velocity of A is 10m/s. Find the velocity of B.

Solution
From figure given, we have
Differentiating both sides w.r.t. t, we get
2xu + 2yv = 0
Here,
Initial velocity, u = 10m/s