What Is the Correct Tension in Each Wire Holding Up the Light Fixture?

  • Thread starter wetcarpet
  • Start date
  • Tags
    Tension
In summary, the conversation discusses a problem involving two wires connected to a ceiling and a hanging light fixture exerting a force of 80N. The wires make a 40 degree angle with the ceiling and the question is to find the tension in the wires. The individual providing the summary assumed it to be a simple trigonometry problem and solved it by dividing the triangle into two parts and using trigonometry equations. However, the software used gave a different answer and the person tried another method, still getting the same answer. The solution was eventually found by dividing the value by 2 as the tension in each string needs to be considered separately.
  • #1
wetcarpet
10
0
There are two wires connected to a ceiling with a light fixture hanging at their ends. The light fixture exerts a force of 80N, while the wires make a 40 degree angle with the ceiling. What is the tension in the two strings? The diagram roughly looks like this:

---------------
- 40 40 -
- -
- -
-
-
80N

I assumed that this was a simple trigonometry problem and set about solving it like so:
{a} I assumed that since the object was not moving downward, there had to be an 80N force exterted upward. Hence, I split the large triangle into two parts using a positive 80N force, making a 90 degree angle with the ceiling, and a 50 degree angle at the base of the larger triangle.
{b} From there I used trigonometry:
cos(50) = 80N/Hyp.
Hyp. = 80N/cos(50)
Hyp. = 124.5N

Yet, the software (Webassign.com) is telling me that the tension is not 124.5N. What am I doing wrong?

P.S.- I also tried assuming that there is not an 80N positive force exerted upward, and thereby tried isolating each X and Y vector for each string seperately. I still got the same answer of 124.5N.
 
Physics news on Phys.org
  • #3
If they want the value for T in each string, you need to divide that value by 2. Resolve the forces perpendicular to the string and you get 2Tsin 40 = 80.
 
  • #4
I thank you kindly, dividing 124.5N by two did work, and I appreciate your explanation as well. :smile:
 
Last edited:

Related to What Is the Correct Tension in Each Wire Holding Up the Light Fixture?

What is a simple tension problem?

A simple tension problem is a type of physics problem that involves calculating the tension force in a string or cable that is being pulled or stretched by an external force. It is often used to determine the strength or stability of a structure or to predict the behavior of objects in motion.

What are the key components of a simple tension problem?

The key components of a simple tension problem include the object or structure being pulled, the string or cable that is exerting the tension force, and the external force that is causing the tension.

How do you calculate tension in a simple tension problem?

Tension can be calculated by using the equation T = F * sinθ, where T is the tension force, F is the external force, and θ is the angle between the string or cable and the direction of the external force.

What factors can affect tension in a simple tension problem?

The tension in a simple tension problem can be affected by the magnitude and direction of the external force, the angle of the string or cable, and the properties of the object or structure being pulled.

What are some real-life applications of simple tension problems?

Simple tension problems have many real-life applications, such as determining the strength of bridges, cranes, and other structures, calculating the tension in ropes used for rock climbing or sailing, and predicting the trajectory of objects in motion, such as a swinging pendulum.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
5K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
681
  • Introductory Physics Homework Help
Replies
1
Views
4K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
861
  • Introductory Physics Homework Help
Replies
3
Views
1K
Back
Top