Two objects A and B are connected by a rigid rod that has a length L. The objects slide along perpendicular guide rails. If A slides to the left with a constant speed v, what is the velocity of B when a=60$^\circ$?
I know the answer is .566 v, but I am completely unsure why.
I have tried saying that $ y=L*sin(a), dy/da=d/da L*sina,dy/da=L cosa,dy/da=Lcos60=L/2 $ but that obviously is the wrong aproach, since I need $dy/dt$, not $dy/da$.