What is Hinge: Definition and 86 Discussions

A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other translations or rotations being prevented, and thus a hinge has one degree of freedom. Hinges may be made of flexible material or of moving components. In biology, many joints function as hinges like the elbow joint.

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1. Sign hanging from massless beam attached to hinge supported by string

Attempted creating equations for zeros of torque and components of forces in x and y as seen in picture. Got lost with having only variables and the d & 2L for the length of the beam. Not sure how to do the question with two points of contact between the beam and the sign. Is the center center...
2. Home project: Kilogram Force on wheel bearings

Hi all. I'm designing a custom spare wheel carrier for my 4wd and currently seeking knowledge on which bearings to use, so I need to work out what force on the bearings will be when it's open (closed will be locked and fully supported!) The example image is simplified for calculation. Close...
3. Trouble Understanding Hinge Axes: Ax ≠ Bx?

I am confused by the drawing of the door with hinges A and B attached. I do not understand why -Ax = Bx. I would have thought that Ax = Bx
4. Maximum angle made by rotating hinge with energy and gravity

Hello! I had a random question while playing around with a garbage can that I hoped y'all could help me walk through: Let's say that I have a hinge on a table, rotating with gravity acting perpendicular to it. Energy is provided into the hinge, let's say by a spring, like so: I want to know the...
5. How to translate force into upward hinging motion between two panels?

Pictured below are two hinged panels that can rotate upward to form an upside-down V. In position 1, the panels are lying flat. In position 2, the panels have folded together and the joined edge is raised up. Normally, in order to actuate this hinging motion, one would need to manually lift the...

7. How to calculate hinge forces?

I have solved problem (A). But I couldn't solve problem (B). Here is my attempt:
8. Static equilibrium of a bar attached to a hinge

item Fx Fy torque(z) rod 0 -mg -mg* (3/2) Fred 0 -Mg (-Mg) * (3/2) hinge -hx hy 0 wire F* cos(theta) F* sin(theta) 3*F* sin(theta) total 0 0 0 theta= tan^(-1) (2/3) = 33.7 degree 3*F* sin(theta) = (8*9.8)* (3/2) + (53*9.8) * (3/2) F= 538.7N tension is 538.7N
9. Post form of a living hinge as a joint

How did you find PF?: google Hi I have a scenario where I just cannot make up my mind when creating this joint and hinge at the same time. Obviously yellow is the hinge, red section to the left has two wings hanging off it held there by two hinges, 250 um. thinking about ultra sonics to...

11. Help with lattice hinge calculations

Can anyone confirm the claim on this site that n is greater or equal to 23 when Theta is 90 degrees and t is 3? My calculations indicate that the argument of arccosine in the numerator has to be very close to 1, but the numerator of the argument (k_laset+t) is 3.1 whereas the denominator...
12. Understanding Hinge Reactions: Debunking Common Misconceptions

https://postimg.cc/JtP2h113 I think I may have forgotten some more basic elements of tension and normal reactions. I do not understand why the vertical component of the normal reaction =Tsin60-15g Because Tsin60-15g is negative when resolving upwards, i would have thought this meant that the...
13. Flag pole finding horizontal force component at hinge.

Homework Statement A flag pole consists of a 80 kg rod of length L = 2 m with a 10 kg point mass attached to the end. The pole is hinged at the bottom and is tied to a horizontal cable as shown. 1. What is the x-component of F (Fx) exerted by the wall on the flag pole at the hinged point A...
14. Construction What is the Door-Like Module Used in Bunker Building?

In this bunker building video,they use a door like module to make the bunker’s entrance.What exactly is that called?And where can I buy it? I can’t clearly see what that is,only knowing it is made by a companie “Diall”
15. Two falling rods connected by a hinge

Homework Statement I uploaded the homework question. This is #1. Homework Equations None directly given The Attempt at a Solution My main difficulty with the problem is that I am convinced it is much easier than my classmates make it out to be. This is graduate mechanics so I'm pretty sure...
16. How is net torque zero about hinge of rod in ball rod system

Homework Statement There are 2 situations- 1)a rod of length L is lying on a smooth horizontal surface with its one end hinged to the ground, a ball traveling with a velocity v hits its other end and comes to rest, How is the net external torque about hinge point O zero? 2) in the second case...
17. Angular momentum of a rod about hinge

Homework Statement A uniform rod (M, L) is rotated about a point L/3 from its left end. Angular momentum about O Homework Equations 1) L=I(cm)w for purely rotating body 2) L(orbital)= M*v(cm)*perpendicular distance(r) 3) L(spin)= I*w The Attempt at a Solution I got the correct answer in two...
18. Where is the hinge point? & what is the moment of inertia of a square?

Homework Statement :[/B] A uniform wire of linear mass density λ having three sides each of length 2a is kept on a smooth horizontal surface. An impulse J is applied at one end as shown in the figure. P is the midpoint of AB. Now answer the following questions. 1) The angular velocity of system...
19. E

Torque on Rod Due to Normal Force at a Hinge

Homework Statement In this diagram, I wondered if there is any torque due to the normal force from the hinge, once the support stick is removed. I also want to know what the normal force would be at the hinge. The cup and ball are to be ignored here (essentially massless). Homework Equations...
20. G

Rotational Torque/Force Problem (rod around hinge)

Homework Statement A Rod of Mass "M" is attached to a two-way hinge on the floor. It is being pulled by a spring (extension spring, so force is pulling the rod to the right, causing it to move clockwise). The hinge is frictionless. the rod has a mass of 5kg evenly distributed the pulling...
21. Electrical hinge mechanism of some sort?

I'm not sure if this is the right thread to post this, but here it is! I'm currently trying to create a prop for one of my friends, since I found it an interesting challenge. This is a simple drawing of what I'm trying to do: The button, battery and so on it not my problem, it's that I've no...
22. Finding magnitude and direction of reaction force

Homework Statement A uniform horizontal rod of mass 4 kg and length 500 mm, is hinged at the left hand side and supported at rest by a chain (S) attached 10 cm from the hinge. Calculate the magnitude and direction of the reaction force on the rod at the hinge. State the principle you have...
23. B Will there be a reaction at the hinge B in this question?

I have solved this question by completely disregarding the reaction at the hinge B. And surprisingly, answer turns out to be correct. Why is that so?
24. Force on a hinge when a rod is being released

Homework Statement : A uniform rod of weight W is free to rotate about a hinge at one end. The hinge is fixed to a wall. If the rod is released from a horizontal position, what force will it exert on the hinge just after being released? a)W b)W/2 c)W/3 d)W/4 choose the correct option[/B]2.The...
25. What is the force exerted by each hinge on the door?

1. Homework Statement The door has a mass of 30 kg, is 200 cm long and 90 cm wide. The hinges are installed at 25 cm from the bottom (R2) and 25 cm from the top (R1). What are is the magnitude of the force exerted by each hinge on the door? The door is in a state of static equilibrium...

Homework Statement Determine the forces at the 3 hinges of closed gate with a wind pressure of 700Pa on the gate. Mass of gate = 236kg wind pressure = 700Pa (apllied perpendicularly to the gate) gate dimensions: 4.1m high, 2.45m wide Distacnce from bottom of door to centre of hinges...
27. Load bearing capacity of a friction hinge?

The door is 4.5 lbs evenly distributed. Width is 7" and length is 19". The door is mounted by using a friction hinge at the center . How to calculate the total load acting on the hinge? What is the maximum load bearing capacity of the hinge? Length of hinge is 3.2" and diameter of pin is .230...
28. Dynamics of Rotational Motion and hinge

One end of a thin, uniform rod is connected to a frictionless hinge as shown in Figure 1. The rod has a length of 0.8 mand a mass of 2 kg. It is held up in the horizontal position (θ=90∘) and then released. 1)Calculate the angular velocity of the rod at θ=90∘. 2)Calculate the angular...
29. Friction Hinge Design: Calculating Bolt Preload and Torque

Hi, I'm looking at a friction hinge design problem. See the image below for details. Looking through a machinist's handbook (pg. 1495), I get a few equations for fastener preload and wrench torque. T = k * Fi * d, where T is wrench torque, Fi is preload, and d is the nominal bolt diameter, and...
30. Door Hinge axial fatigue testing equipment

Well some one have any experence related to axial fatigue testing equipment designing? Have to discuss some concepts and need the feedback.
31. Friction Hinge Design using spring pins

Hi As described in my previous post I am looking to make a foldable mechanism of an arm hinge. I have changed my design into the one shown in attached image. I plan to use spring split or coil pin to constrain radial movement in the hinge (yellow and red). Adding a bolt through the hinge...
32. Vibration proof hinge and lock

Hi All. I am stuck in a problem. Please check the image attached. It's part of a foldable mechanism of a quad copter arm. The red part is fixed to the body, the grey part is fixed to arms. The transparent part is a threaded collar/sleeve. The yellow part is a stopper. The hinge is a connecting...
33. What is the direction of hinge force?

how to find direction of hinge force? for example ,if a disc is hinged at a point on it's circumference and is exhibiting a rotational motion due to gravity,what is the hinge force?
34. Lagrangian of Pendulum with Oscillating Hinge

1.) The Problem Statement: a.) Find the Lagrangian of a pendulum where the height of the hinge is oscillating in the y direction and is is defined as a function ##y_0=f(t)## b.) Add a function (a gauge transformation) of the form ##\frac{d F(\theta,t)}{dt}## to the original lagrangian...
35. What does Hinge Reaction signify ? How do i calculate it ?

I recently came across a lot of problems where components of Hinge Reaction were asked along different axis . What is hinge reaction ? How do i calculate it ? How do i find its direction ? Does it change angular velocity / acceleration of the body ?Sample Question ) A square lamina of side...
36. Unsure of mechanics problem, circular door on hinge...

1. In the attached imjage, the centre of gravity of an open door acts at G equal to 255N; a) Determine the x,y,z, components of reaction at the hinge A in equilibrium b) Determine the force along CB Little stuck with this problem, obviously this falls under resolving forces. I assumed Az,Ay = 0...
37. Finding Acceleration and Reaction Forces in Rotating Thin Rod on a Hinge

Homework Statement A thin rod of mass 0.620 kg and length 1.08 m is at rest, hanging vertically from a strong, fixed hinge at its top end. Suddenly, a horizontal impulsive force (14.2 i ) N is applied to it. (a) Suppose the force acts at the bottom end of the rod. Find the acceleration of its...

Homework Statement So this is a small part of a much larger problem that I'm working on that I don't want to post here. Basically, I want to find the contribution to the torque about the hinge of a ladder BY the mass of the ladder itself. A ladder is propped open at an angle α. What is the...
39. How to find cord tension and hinge force?

Homework Statement A 5 kg 10 m beam is hanging from a wall. The angle between the cord and the wall is 30 degrees, and a 10kg mass is situated one meter away from the wall. How do I solve for cord tension and hinge force? Homework Equations Torque_cw=Torque_ccw? The Attempt at a Solution it...
40. Distributing hinge force laterally?

Hi guys, this is my first post on here and my first real delve into physics beyond simply having a keen interest in mechanics and car-related physics, so apologies if my terminologies and such are a bit off. Basically, I was having a debate with my father and I want to know if there is a way to...
41. What forces do flanged bushes on a door hinge experience?

Hi. I have a door mounted on 2 hinges, aligned on a vertical axis. The hinge shafts run in flanged plain bushes. I'm trying to work out what forces the flanged bushes will see. The door weighs 100Kg, with the centre of mass at the centre of the door. The door is 2m wide and 2m vertically...
42. Tension and Hinge Force Problem

Homework Statement The 135-N uniform beam from which 14-N wooden blocks are suspended is pinned to the ground. The beam is then supported by a cable (attached at the center of the beam) to allow the blocks to hang freely. If the blocks are attached two-fifths and three-fifths of the way...
43. Pivoting Antenna Deployment Hinge

Hello, I am an electrical engineering graduate student building an antenna which will be mounted under the fuselage of twin engine airplane which will be taking remote sensing measurements. Besides the antenna design I have also been tasked with developing the method of deployment as well...
44. How Do You Calculate Tension in a Cable and Force on a Hinge?

Homework Statement A 20 kg uniform beam 10m long is attached to a wall with a cable. The cable is attached to the middle of the beam at 90º to the beam. A box of mass 50 kg is suspended from the beam as shown. Determine the tension in the cable. Determine the force acting on the hinge at...
45. The Mystery of Door Hinge Longevity: How Do They Last So Long?

The door hinges inside my place are pretty old; I'd guess a few decades though I don't have any way of knowing for sure. I do have experience with metal on metal rubbing and degradation. So I wonder, why can door hinges open and close for a long time, and not wear away? I don't think I've...
46. Find Hinge Force of Rod Undergoing Circular Motion

Homework Statement A rod of mass m and length l is hinged about its end A and is vertical initially. Now the end A is accelerated horizontally with acceleration a=g m/s^2. The hinge reaction when the rod becomes horizontal is ? Homework Equations See the attached picture for relevant...
47. What is the Magnitude of F2 in a Hinged Beam Torque Problem?

Homework Statement The massless bar, hinged at A, is inclined at an angle θ = 28.0° and subjected to horizontal and vertical forces F1 and F2, as shown. If L1 = 2.30 m, L2 = 1.00 m, F1 = 31 N, and the beam is in static equilibrium, what is the magnitude of F2? Homework Equations...
48. Inverse Dynamics - 2 Rigid Bodies connected with hinge

I am trying to simulate and animate inverse dynamics. So I need to calculate torques. I started out by just taking a rod which rotates about its COM, applied a torque and then just used \tau=I\alpha to make sure I get back the same torque I applied. Next, I attached the rod to the ground with...
49. Horizontal Force on a Gate Hinge?

A door is attached to a frame by two hinges and is at equilibrium. All forces and torques are therefore balanced. The door has a mass of 10.5kg, a width of 1.1m, and the two hinges are 0.7m apart. Find the direction and magnitude of the horizontal force applied to the door by the top hinge? I...
50. Current in a rectangle on a hinge

Homework Statement Figure 29-36 shows a rectangular, 15-turn coil of wire, 10 cm by 5.0 cm. It carries a current of 0.90 A and is hinged along one long side. It is mounted in the xy plane, at an angle of 30° to the direction of a uniform magnetic field of 0.50 T. Find the magnitude and...