Newton's First Law and Tension in Ropes

Introduction

• Discussion focuses on tension in ropes holding up weights (bricks, person, etc.)
• Equals mass distribution and net force analysis

Key Concepts

Tension Distribution in Ropes

• Three ropes: Weight (10 Newtons) split equally among ropes
  • Each rope: ~3.3 Newtons of tension
• Two ropes: Weight (10 Newtons) split equally
  • Each rope: 5 Newtons of tension
• One rope: Full weight (10 Newtons) on one rope
  • Rope tension: 10 Newtons
• Net force analysis shows balance (net force = 0) ensures stability

Example - Boy on Scales

• Mass of Boy: 200 Newtons (50 pounds)
• Equal distribution across two scales
  • Each scale: 100 Newtons
• Leaning to one side shifts weight but total force remains 200 Newtons
• Examples extend to similar situations like girl on a trapeze

Ropes Supporting a Painter

• Painter Weight: 500 Newtons
• Two ropes: Each takes 250 Newtons (totaling 500 Newtons)
• One rope scenario: Rope takes full 500 Newtons, leading to potential rope failure if the limit is 300 Newtons
• Net force zero principle examined through painter’s equilibrium

Scaffold Example

• Scaffolds with weights and forces
  • Weights: 100 Newtons each on either side
  • Total Weight: 200 Newtons
• Supporting forces on ropes must equal downward forces to maintain equilibrium
  • If the net force is not zero, scaffold and painters would move/not be stable
  • Walking painter shifts weight distribution but the net force equilibrium principle stays

Summary

• Importance of balancing forces (Newton's First Law) to maintain stability
• Variety of setups (ropes, scales, scaffolds) demonstrate the practical application of tension and net force equilibrium