Does the Bottom Hinge's Vertical Force on a Door Produce Torque?

[hks118]

Homework Statement

This is a part of a larger problem, but I'm unsure of one part.
Picture a door with its center of mass in its geometric center. The door is hanging on two hinges, one at the top and one at the bottom. If the pivot point while measuring torques is considered to be the top hinge, does the vertical component of the force that the bottom hinge exerts on the door produce and torque?

Homework Equations

Torque=force*lever arm

The Attempt at a Solution

I don't think it does because there is no displacement in the x direction from the pivot, but I'm not sure

 

[tiny-tim]

Hi hks118!

If the pivot point while measuring torques is considered to be the top hinge, does the vertical component of the force that the bottom hinge exerts on the door produce and torque?
…
I don't think it does because there is no displacement in the x direction from the pivot

That's correct … the "lever arm" is the distance of the pivot point from the line of force.

Here, the line of the force (the vertical component of the lower hinge reaction) goes through the pivot, so the distance is zero.

 

[hks118]

Hi hks118!


That's correct … the "lever arm" is the distance of the pivot point from the line of force.

Here, the line of the force (the vertical component of the lower hinge reaction) goes through the pivot, so the distance is zero.

Thanks! I can finish the problem in good conscience now