As you are leaving a building, the door opens outward. If the hinges on the door are on your right, what is the direction of the angular velocity of the door as you open it? a. up to the ceiling/sky.
b. down to the floor/ground.
c. to your left.
d. to your right.

b. down to the floor/ground

Explanation:

The direction of the angular velocity can be easily found by the use  of right hand rule. This rule states that when we curl the fingers of right hand in the direction of the rotation of the object, the direction of the thumb gives the direction of angular velocity. We apply this rule to our situation. Since, the door opens outward and the hinges are on right, it means that the rotation of door is clockwise. So, when we curl the fingers of right hand in clock wise direction, the thumb will point in downward direction. So, the direction of angular velocity will be down to the floor/ground.

The correct option is:

b. down to the floor/ground

It is hydraulic. The key is to remember that the pressure will be constant through the whole liquid thus the force requuired on the left side will be much less and proportional to the difference in area of the right and the left. Do you need actual calculations or can you figure it out from this? Think Pascal's principle