Special Relativity Problem (1.364, Irodov)

[shanu_bhaiya]

Homework Statement

The rod AB oriented parallel to the x' axis of the reference frame K' moves in this frame with a velocity v' along it's y' axis. In its turn, the frame K' moves with a velocity V relative to the frame K as shown in Figure. Find the angle (theta) between the rod and the x-axis in the frame K.

Homework Equations

Lorentz Transformation:
x' = (x-Vt)/(1-(V/c)²)^1/2; y = y' (Doubtful in this case)
v_x' = v_x - V/(1-v_xV/c²);
v_y' = v_y (1-(V/c)²)^1/2/(1-v_xV/c²).

The Attempt at a Solution

As far as I know that the rod AB in frame K should not be tilted at all, I mean it must remain horizontal if x and x' axis of K and K' frames coincide, or am I wrong? So, my only problem is that - "Is it possible for rod to be tilted in frame K?"

 

[shanu_bhaiya]

In image, by fault there are two v' written for the velocity of rod, so don't be confused.

And on emore thing the problem is 1.364 from Problems in General Physics - I. E. Irodov.