An overhead door is guided by wheels at a and b that roll in horizontal and vertical tracks. when θ = 40°, the velocity of wheel b is 1.8 ft/s upward. determine the angular velocity of the door and the velocity of end d of the door.

I think the situation is modeled by the scenario in the attached image. Some specific values seem to be missing (like the height of door )...

The door forms a right triangles that satisfies

We also have

so if you happen to know the height of the door, you can solve for and .

is fixed, so

We can solve for the angular velocity :

At the point when and ft/s, we get

i would say the answer is food.

hope this !