Physics · Unit 2: Dynamics ·  Project 2-1-4

Force Table Balancing Act

🚀 PROJECT

You're given two known forces pulling on a ring at fixed angles. Find the third force that holds it perfectly still — then check your work by actually balancing it on the table  ·  3 class days

New SkillFx = F cosθ,  Fy = F sinθequilibrant = −resultant

🧭 Project Summary

A force table is a circular table with pulleys mounted around its edge. Strings run from a central ring, over the pulleys, to hanging weights — each string pulls the ring with a force whose size depends on the weight, and whose direction depends on which pulley it runs over. Your teacher will assign you two forces, each with a known magnitude and angle.

Your job: calculate exactly the third force — magnitude and angle — that would hold the ring perfectly still at the center of the table. Then set that third string up for real, hang the weight you calculated, and see how close the ring actually sits to dead center.

The three days

1Learn to add force vectors using components — a new skill this project needs.
2Calculate your predicted balancing force from your assigned two forces.
3Test it on the real force table, compare, and write up your results.

Turn in

  • Your predicted balancing force (magnitude and angle) versus what you actually measured
  • A free-body diagram of the ring showing all three forces in equilibrium

Why it matters

Every force you've drawn so far in Unit 2 has pointed in one of a handful of simple directions — straight down, straight up, left, right. Real forces rarely cooperate that neatly. This project is where force vectors grow up: any angle, any combination, added correctly using math instead of a guess.

🧩 Before You Start — Prerequisite Check

This project leans on Lessons 2-1-1 and 2-1-2, plus a brand-new skill — adding 2D force vectors — that gets taught inside this project's own Deep Dive.