How Do You Calculate Tension in a Cable and Compression in a Brace?

In summary, to find the tension in the cable and compression in the boom supporting a 235lb sign, draw a free body diagram and use Newton 1 in x and y direction to solve for the components. The answers are 390.5 and 311.9.
  • #1
copyfilew
3
0

Homework Statement


A 235lb sign is supported from a wall by a cable inclined 37 degrees with the horizontal, and a brace perpendicular to the wall. Find the tension in the cable and the compression in the boom.

The answers are 390.5 and 311.9. But I have no idea how they got to those numbers. :S

Homework Equations


No idea?


The Attempt at a Solution



Tried to find the x/y components of the vectors, but I'm confused now.
 
Physics news on Phys.org
  • #2
copyfilew said:

Homework Statement


A 235lb sign is supported from a wall by a cable inclined 37 degrees with the horizontal, and a brace perpendicular to the wall. Find the tension in the cable and the compression in the boom.

The answers are 390.5 and 311.9. But I have no idea how they got to those numbers. :S

Homework Equations


No idea?


The Attempt at a Solution



Tried to find the x/y components of the vectors, but I'm confused now.
One way is to draw a free body diagram of the sign and identify the forces acting on it ...its weight down, the cable tension along the length of the cable (which has an x and a y component), and the brace compression along its length (x component only). Then use Newton 1 inthe x and y direction to solve for the components.
 
  • #3


I would approach this problem by first drawing a free body diagram of the sign and the forces acting on it. From the problem statement, we know that there are two forces acting on the sign: the tension in the cable and the compression in the boom. The sign itself has a weight of 235lb, which can be represented as a downward force.

Next, I would use trigonometry to find the components of the forces acting on the sign. The tension in the cable can be broken down into horizontal and vertical components, with the vertical component opposing the weight of the sign. The horizontal component of the tension will be equal to the compression in the boom, as they are perpendicular to each other.

Using the given angle of 37 degrees, we can find the values of the horizontal and vertical components of the tension using basic trigonometric functions (sin, cos, tan). Once we have the values for the components, we can use the Pythagorean theorem to find the magnitude of the tension, which is equal to the compression in the boom.

The tension in the cable can then be found by adding the horizontal and vertical components together. This will give us a value of approximately 390.5lb. Similarly, the compression in the boom can be found by taking the square root of the sum of the squares of the horizontal and vertical components, which will give us a value of approximately 311.9lb.

In summary, the tension in the cable and the compression in the boom can be found by using trigonometry and the Pythagorean theorem to break down the forces and find their magnitudes. This approach is based on the principles of Newton's laws of motion and can be applied to various problems involving forces and their components.
 

FAQ: How Do You Calculate Tension in a Cable and Compression in a Brace?

What is the tension of a cable?

The tension of a cable refers to the amount of force applied to the cable to keep it taut or in a state of equilibrium. It is often measured in units of newtons (N) or pounds (lbs).

How is the tension of a cable calculated?

The tension of a cable can be calculated using the formula T = F * L, where T is the tension, F is the applied force, and L is the length of the cable. Other factors such as the weight of the cable and external forces may also need to be taken into account.

What factors affect the tension of a cable?

The tension of a cable is influenced by several factors, including the weight of the cable, the angle at which the cable is pulled, the material and thickness of the cable, and any external forces acting on the cable.

How does the tension of a cable impact its strength?

The tension of a cable directly affects its strength. As the tension increases, so does the stress on the cable, which can lead to stretching or even breaking if the tension is too high. It is important to carefully calculate and monitor the tension of a cable to ensure its safety and effectiveness.

Can the tension of a cable be changed?

Yes, the tension of a cable can be adjusted by changing the applied force or the length of the cable. However, it is important to consider the maximum tension that the cable can withstand before making any adjustments to avoid damage or failure.

Back
Top