# Kinematics - relative velocities

1. Jan 17, 2007

### srh

1. The problem statement, all variables and given/known data

I have attached a picture of the situation. Small Wheels attached to the ends of rod AB roll along two surfaces. Knowing that at the instant shown the velocity vA of wheel A is 1.5 m/s to the right and the relative velocity vB/A of wheel B with respect to wheel A is perpendicular to rod AB, determine the relative velocity vB/A and velocity vB of wheel B.

2. Relevant equations
vA+vB/A=vA

3. The attempt at a solution

I understand that vA+vB/A =vA. I know that the component of vA is 1.5m/s in the x direction. The problems that we have done were all with right angles. I know another way to figure out the problem is to draw the vectors but we don't have all the angles. I can't seem to figure out how to find the angle that the rod AB makes w/ the x-axis. Is there a formula that I am missing? I'm just not sure where to start.

2. Jan 18, 2007

### Staff: Mentor

Sorry, srh, there doesn't appear to be a picture attached. Can you please try again?