Calculating Force and Weight in a Simple Statics Problem

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SUMMARY

The discussion focuses on calculating the force exerted on a pole by a 170lb man hanging from a 100-foot rope at a 5.74-degree angle from a cliff. The upward force component is determined using the equation F * sin(84.26) = 170lb, leading to F = 170/sin(84.26). The horizontal force component, which the pole must counteract, is calculated as F*cos(84.26), resulting in approximately 17 pounds. This problem exemplifies a simple statics scenario, solvable through basic algebra without advanced calculus.

PREREQUISITES
  • Understanding of basic trigonometric functions (sine, cosine)
  • Familiarity with statics concepts, specifically force components
  • Knowledge of algebraic manipulation for solving equations
  • Awareness of the method of joints or method of segments in statics
NEXT STEPS
  • Study the method of joints in statics for analyzing forces in structures
  • Learn about the method of segments for solving complex statics problems
  • Explore trigonometric identities and their applications in physics
  • Review basic principles of equilibrium in static systems
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This discussion is beneficial for physics students, engineering students, and anyone interested in understanding basic statics and force calculations in real-world applications.

nikneven
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So, I have recently run across a real life application of things I haven't used in 10 years.

A 170lb man is hanging from a 100 foot rope off the edge of a vertical cliff. He is pushing himself out from the rock with a 10 foot pole. The angle of the rope from the cliff is 5.74 degrees. How much force / or weight is on the pole?

How would i figure this out? If some one could tell me, using very small words, and pretending I didn't take advanced calculus and physics...

I really would like to understand this again.

Thank You.:blushing:
 
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The magnitude of the force exerted by the rope we denote by F. The upward component of this force is F * sin(84.26), which is equal to 170lb since it must balance the man's weight. So F = 170/sin(84.26). But the horizontal component, which the pole must balance, is F*cos(84.26), or 170*cot(84.26), which is about equal to seventeen pounds.
 
Its a simple statics problem. Just sum the forces in the X and Y dimensions and solve for the unknowns, simple algebra no calc needed. Look up method of joints or methods of segments for more details.
 

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