Torque-Sign hanging from a cable

  • Thread starter Thread starter sam2k2002
  • Start date Start date
  • Tags Tags
    Cable
Click For Summary
SUMMARY

The discussion focuses on calculating the maximum mass of a sign suspended from a pole using torque principles. The problem involves a 120cm-wide sign hanging from a 5.4 kg pole, supported by a cable with a maximum tension of 330N. The user initially attempted to calculate the maximum mass using the equation T = r*F*sin(phi) but neglected to account for the weight of the pole in the torque balance. The correct approach requires summing torques about the point where the pole meets the cable, ensuring all forces, including the pole's weight, are included in the calculations.

PREREQUISITES
  • Understanding of torque and its calculation
  • Familiarity with the concept of tension in cables
  • Knowledge of basic physics principles, including force and weight
  • Ability to apply trigonometric functions in physics problems
NEXT STEPS
  • Review the principles of torque and equilibrium in static systems
  • Study the effects of additional forces, such as the weight of the pole, on torque calculations
  • Learn about the application of trigonometric functions in physics problems
  • Explore examples of similar problems involving tension and torque in engineering contexts
USEFUL FOR

This discussion is beneficial for physics students, engineering students, and anyone interested in understanding the mechanics of static equilibrium and torque calculations in real-world applications.

sam2k2002
Messages
10
Reaction score
0
Torque--Sign hanging from a cable

Homework Statement



A 120cm-wide sign hangs from a 5.4 kg, 200cm-long pole. A cable of negligible mass supports the end of the rod as shown in the figure

What is the maximum mass of the sign if the maximum tension in the cable without breaking is 330N?


http://session.masteringphysics.com/problemAsset/1070549/3/12.P66.jpg"

Homework Equations


T = r*F*sin(phi) = F * d (d = moment arm length)


The Attempt at a Solution



I set the Torque provided by the tension in the cable equal to the torque provided by the weight of the sign because the cable will break when the mass is just above the mass at this point.

(330N)(2m)(sin 51) = (1.2m)(9.81)(max_mass)

with this I get the max_mass to = 43.6kg, a wrong answer. Can anyone help me out here? Thanks.
 
Last edited by a moderator:
Physics news on Phys.org
What happened to the weight of the pole? What point are you summing torques about?
 

Similar threads

Does distance affect torque in hanging sign problem?
  • · Replies 42 ·
2
Replies
42
Views
4K
Cable car with 2 cable arrangement
  • · Replies 1 ·
Replies
1
Views
7K
Tension and net torque in a cable
  • · Replies 10 ·
Replies
10
Views
6K
Torque and Rotational Equilibrium with a slanted Rod/Cable
  • · Replies 7 ·
Replies
7
Views
3K
Sign hanging from massless beam attached to hinge supported by string
  • · Replies 10 ·
Replies
10
Views
3K
Calculating Tension and Net Force in Suspended Cable System
  • · Replies 3 ·
Replies
3
Views
3K
Why is the tension in a massive cable always tangent to its portion?
  • · Replies 5 ·
Replies
5
Views
2K
What is the tension in the right cable?
  • · Replies 4 ·
Replies
4
Views
3K
Solving Tension in Cable Homework Statement
  • · Replies 2 ·
Replies
2
Views
13K
Calculating Linear and Angular Motion in a Drum and Cable System
  • · Replies 6 ·
Replies
6
Views
5K