Static Equilibrium and tension of a cord

In summary, a non-uniform bar of weight 12.5 N is suspended in a horizontal position by two massless cords. The angle between cord 2 and the vertical is 27.5°. The bar has a length of 6.0 m and its center of gravity is located 4.4 m from the left-hand end. To find the tension in cord 2, an equation was set up using the forces and torque applied to the bar. However, the torque equation provided was incorrect as it did not have the correct dimensions. The correct torque equation should be -mgL + T2cos(27.5)*6.
  • #1
chaotixmonjuish
287
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A non-uniform bar of weight W = 12.5 N is suspended at rest in a horizontal position by two massless cords. The angle φ between cord 2 and the vertical is equal to 27.5°. The bar has a length L = 6.0 m and the distance of its center of gravity from the left-hand end of the bar is 4.4 m. What is the tension in cord 2?
img:http://i242.photobucket.com/albums/ff106/jtdla/prob01a-2.gif

My lab partner and I set up this equation:
Fx: T2*cos (27.5)-T1*cos(theta)=0
Fy: T2*sin(27.5)+T1*sin(theta)-mg=0

Torque: -mgL-T2*cos(27.5)=0

I'm not sure if that L is 4.4 or 6, nor do I know if I am starting this properly.
 
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  • #2
Eqn for Fx and Fy are correct, but torque is incorrect; firstly, dimensionally its wrong and secondly, which is cord 1? left side one or right side one?
 
  • #3
Cord 1 is on the left
 
  • #4
k. then L should be 4.4
 
  • #5
so is the torque equation correct if i use 4.4
 
  • #6
dimensionality?
 
  • #7
I'm afraid I don't understand
 
  • #8
chaotixmonjuish said:
Torque: -mgL-T2*cos(27.5)=0
T2*cos(..) has dimensions of force and mgL has dimensions of work.
 
  • #9
so would torque be the length of the bar*-mg
 
  • #10
torque is : -mgL + T2cos(27.5)*6 (6 is the perpendicular distance of force vector from the point at which you are taking torque)
 
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FAQ: Static Equilibrium and tension of a cord

What is Static Equilibrium?

Static Equilibrium is a state in which all forces acting on an object are balanced, resulting in no net force and therefore no acceleration. In other words, the object is at rest or moving at a constant speed in a straight line.

How is Static Equilibrium related to the tension of a cord?

When an object is in Static Equilibrium, the tension in a cord or rope is equal to the force exerted on the object by that cord or rope. This means that the tension in the cord is a contributing factor to maintaining the object's state of equilibrium.

What factors affect the tension in a cord?

The tension in a cord is affected by the force exerted on it, the length and stiffness of the cord, and the angle at which it is pulled. Additionally, the weight of the object being supported by the cord can also affect the tension.

How can tension in a cord be calculated?

Tension in a cord can be calculated using the formula T = mg + ma, where T is the tension, m is the mass of the object, g is the acceleration due to gravity, and a is the acceleration of the object. Alternatively, the tension can also be calculated using the equation T = Fsinθ, where F is the force exerted on the cord and θ is the angle at which it is pulled.

Why is understanding Static Equilibrium and tension of a cord important?

Understanding Static Equilibrium and tension of a cord is important in many fields, including engineering, physics, and architecture. It allows us to accurately predict and analyze the forces acting on objects and structures, ensuring their stability and safety. It also helps us to design and build structures that can withstand the forces they will encounter in real-world scenarios.

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