Solve Torque w/ 2 Supports & Equilibrium Problems Easily

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SUMMARY

This discussion focuses on solving torque and equilibrium problems involving uniform planks and beams. A specific example involves a 6.0 m plank weighing 400 N balanced on two supports 3.7 m apart, with a 65 kg load needing to be positioned without tipping. Another example features a 7.2 m beam weighing 480 N with weights hung at specific distances, requiring calculation of the fulcrum position for equilibrium. The key principle discussed is that the moments around the fulcrum must be equal for the system to remain balanced.

PREREQUISITES
  • Understanding of torque and equilibrium principles
  • Familiarity with calculating moments (torque = force x distance)
  • Basic knowledge of weight calculations (weight = mass x gravity)
  • Ability to set up and solve algebraic equations
NEXT STEPS
  • Study the principles of static equilibrium in physics
  • Learn how to calculate moments for various load configurations
  • Practice solving problems involving multiple forces and supports
  • Explore the use of free-body diagrams to visualize forces and moments
USEFUL FOR

Students in physics or engineering courses, educators teaching mechanics, and anyone seeking to improve their problem-solving skills in torque and equilibrium scenarios.

VelvonVeden
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1. A 6.0 m long uniform plank is balanced on two supports with are 3.7 m apart. The plank weighs 400N. If one of the supports is 0.5m fro one end of the plank, how far from the other end can a 65 kg load hang without the plank tipping over?

and

A 7.2 m long beam AB weighing 480 N has its center of gravity 2.4 m from A. A 5.0 kg mass and a 2.5 kg mass are hung from the beam at 1.2 m and 0.8 m distances from B respectively. Calculate the position where the fulcrum is placed to keep the beam in equilibrium horizontally.


2. If someone could give me tips on a method of generally approaching such problems, I would appreciate itAccording to the laws of equilibrium, the moments of the force on with either side of the fulcrum must be equal, and the force acting downward must be equal to the opposite force acting upward.

Keeping that in mind I calculated the weight of 65 kg load mg - (65)(9.8) =637. I have had this problem for a while and have tried so many different methods i can't remember them all. Calculating the weights and trying to make them equal. Calculating the moments. Adding subtraction dividing etc. my instructor refuses to help.

I am stuck, I have no idea how to attack it now simple. Please help! I have four other similar problems.
 
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Please post at least one attempted solution, showing all working. Keep it all symbolic, not plugging in any numbers yet.
 

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