A ladder is resting against a vertical wall.The top slides down in the -y direction and the bottom in the -x direction.

What is dtheta/dt (where theta is the angle btw x axis and ladder)when the top of the ladder has -2.6m/s j and the angle btw the x axis and ladder is 26deg.

I have worked out that the i component of vel is 0.634039m/s,but dont know how to calculate dtheta/dt.

Length of ladder is 0.155meters

ans=-18.663 rad/s