Analyzing Forces in a Weightless Beam AO

  • Thread starter Femme_physics
  • Start date
  • Tags
    Beam Forces
In summary, the weight on the beam is held at the xy plane by a weightless AO. The weight is attached to a ball joint at points C and A, and has horizontal and slanted wires attached to it. At point E, a force acts on the beam and the beam's shape is OKAD. The angle between the force and the beam is 60.
  • #1
Femme_physics
Gold Member
2,550
1

Homework Statement



http://img84.imageshack.us/img84/1715/given2.jpg

A weightless beam AO is held in a horizontal position (at the xy plane) as described. At its tip O the ball is attached to a ball joint, and at points C and A its tied via wires. horizontal wire CD and slanted wire AB, whose in the plane parallel to xz. At point E acts on the beam vertical force Q. The shape OKAD is a rectangle (look at the upper view in the drawing).

Given:


http://img35.imageshack.us/img35/9106/given1.jpg


The Attempt at a Solution



http://img215.imageshack.us/img215/2376/per1v.jpg

http://img845.imageshack.us/img845/9779/per2.jpg

They give out Oz as 0.86666 [kN]. I doubt this could just be a rounding error?
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Hey, I recognize this problem! :smile:

Femme_physics said:
They give out Oz as 0.86666 [kN]. I doubt this could just be a rounding error?

I agree, but I get 0.9 kN as well...
 
  • #4
It looks like you got the components of TCD switched in your moment equation.

Hint: You can calculate the moment about O due to TCD more simply since you know the angle between the lever arm and the force.
 
  • #5
It looks like you got the components of TCD switched in your moment equation.

Did I really? What is the angle from Tcd to the Y axis? It's 60! I reckon I got it right.

Look, I made it more clearly on powerpoint so you'll see exactly what I'm seeing

http://img11.imageshack.us/img11/7708/metersandeverything.jpg

According to the axes, I used the right distances and angles
Hint: You can calculate the moment about O due to TCD more simply since you know the angle between the lever arm and the force.

but I don't have to use the diagonal distance.
 
Last edited by a moderator:
  • #6
Femme_physics said:
Did I really? What is the angle from Tcd to the Y axis? It's 60! I reckon I got it right.

According to the axes, I used the right distances and angles
Yeah, I think you are right. It's just a calculation error then. I haven't been able to reproduce your answer from your equation. I get [itex]T_{CD}=\sqrt{3}~\mathrm{kN}[/itex].
but I don't have to use the diagonal distance.
I have no idea what you mean. The torque τ is just τ = rF sin θ = (0.6 m)TCD sin 60.
 
  • #7
Thanks :smile: I "think" I solved it. I'll post my full solution this evening scanned. Only Oz is different. I noticed the solution manual makes it out to be 1.5 kN, whereas it really should be 0.9 kN
 

FAQ: Analyzing Forces in a Weightless Beam AO

1. What is a weightless beam in terms of physics?

In physics, a weightless beam refers to a hypothetical scenario where a beam or object is considered to have zero mass. This means that it experiences no gravitational force and is not affected by the acceleration due to gravity.

2. How do you analyze forces in a weightless beam?

To analyze forces in a weightless beam, you will need to use the principles of static equilibrium. This means that the sum of all forces acting on the beam must equal zero, and the sum of all torques (rotational forces) must also be equal to zero.

3. What are the forces acting on a weightless beam?

In a weightless beam, there are typically two types of forces acting: external forces and internal forces. External forces include any applied forces, such as a weight or a support. Internal forces include the tension and compression forces within the beam itself.

4. How does the angle of the beam affect the forces acting on it?

The angle of the beam can affect the forces acting on it by changing the distribution of the forces. For example, if the beam is at an angle, the weight of the object on the beam will be split between the vertical and horizontal components, resulting in different forces acting on the beam.

5. Can we apply the same principles of analyzing forces to a real-world weightless beam?

While the concept of a weightless beam is purely theoretical, the principles used to analyze forces in a weightless beam can be applied to real-world beams. However, in reality, all objects have some mass and are affected by gravity, so the analysis may not be entirely accurate.

Similar threads

Solving Tensions and Reaction Forces of Pole AB
Replies
12
Views
3K
Calculating Force and Motion on an Inclined Plane
2
Replies
45
Views
5K
How Are Reaction Forces Directed at Points A and D in a Supported Beam?
Replies
1
Views
8K
Rotation Dynamics: Finding Tension and Force Components in a Hanging Beam System
Replies
6
Views
5K

Hot Threads

Recent Insights

Back
Top