Torque & Rotational Equilibrium
Balance a beam by adjusting masses, distances, and pivot point. Visualize clockwise and counterclockwise torques and observe rotational equilibrium conditions in real time.
WHAT IS TORQUE & ROTATIONAL EQUILIBRIUM?
Torque is the rotational equivalent of force. It measures how effectively a force can cause an object to rotate around a pivot point. For an object to be in **static equilibrium**, two conditions must be met: the net force must be zero (no linear acceleration) and the net torque must be zero (no rotational acceleration). This concept is fundamental for analyzing levers, seesaws, and structural beams.
HOW TO USE THIS VISUALIZATION
1. **Place Masses on the Lever**: Drag different weights to various distances from the fulcrum. 2. **Balance the Seesaw**: Find the combination of mass and distance () that results in zero net torque. 3. **Vary the Force Angle**: Observe how applying a force at an angle other than reduces the effective torque.
CORE FORMULAS
AP EXAM CONNECTION
Unit: Unit 5: Torque and Rotational Dynamics (Topic 5.1)
Learning Objective: 5.1.1
COMMON MISCONCEPTIONS
- Thinking that a large force always produces a large torque (it depends on the lever arm).
- Forgetting that the net force can be zero while the net torque is non-zero (e.g., a couple).
- Using the wrong distance (must be the perpendicular distance to the line of action).
KEY TAKEAWAYS
- Torque depends on force, lever arm distance, and angle.
- Static equilibrium requires both net force and net torque to be zero.
- Clockwise torques must equal counter-clockwise torques for balance.
- Lever arms are perpendicular distances to the line of action.
PRACTICE QUESTIONS
Q1 (QUANTITATIVE): A 10 kg mass is placed 2 meters from the fulcrum. Where must a 20 kg mass be placed to balance the lever?
Show Answer & Explanation
Answer: 1 meter from the fulcrum.
Explanation: For equilibrium, , so . meter.
