What Are the Vertical and Horizontal Forces on Door Hinges?

Click For Summary
SUMMARY

The discussion focuses on calculating the vertical and horizontal forces acting on door hinges, specifically for a door with weight Mg, width W, and length L. The top and bottom hinges are positioned a distance d from the top and bottom of the door, respectively. The horizontal forces are derived using torque equations, leading to the conclusion that the lower hinge exerts a force opposite to that of the upper hinge. For vertical forces, it is established that each hinge supports half the weight of the door, or Mg/2.

PREREQUISITES
  • Understanding of static equilibrium principles, specifically ∑F = 0 and ∑τ = 0.
  • Basic knowledge of torque calculations and their application in mechanical systems.
  • Familiarity with the concepts of vertical and horizontal force components.
  • Ability to visualize force interactions in static structures.
NEXT STEPS
  • Study the application of torque in static equilibrium problems.
  • Learn about the mechanics of door hinges and their force distributions.
  • Explore advanced topics in statics, such as the effects of additional loads on hinge forces.
  • Investigate real-world applications of force analysis in mechanical engineering.
USEFUL FOR

Students studying physics or engineering, mechanical engineers, and anyone interested in understanding the mechanics of door systems and static force analysis.

issisoccer10
Messages
35
Reaction score
0

Homework Statement


A door with weight Mg has a horizontal width W and a vertical length L. There are two hinges that hold up the door along the right side of the door. The top hinge is a distance d from the top of the door and the bottom hinge is a distance d from the bottom of the door. What are the vertical and horizontal forces on each of the hinges?


Homework Equations


∑F = 0
∑τ = 0



The Attempt at a Solution


As for the horizontal forces, I believe that using torques, based on the the force on the upper hinge, F * (L-2d) = Mg(W/2). Then the horizontal force on the lower hinge would just be equal to that but in the opposite directon.
However, as for the vertical components, I'm a little stuck. Some similar questions have been asked in these forums, but they all seem to say something along the lines of "each hinge supports the weight of the hinge equally" or "only the top hinge supports the weight of the door." Yet my question does nothing of the sort. How should I go about finding the vertical components of the doors? I have the same question as for which direction each of the horizontal compontent of the hinges point. Is there a right or wrong answer for their direction, as long as they are opposite, since there is no indication in the question?
 
Physics news on Phys.org
the direction of the horizontal forces is easy to visualize. the bottom hinge tries to push the door away and the top one tries to pull it back. as for the vertical forces i think you assume that each one is mg/2
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
13K
Replies
1
Views
6K
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
8
Views
6K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K