Moments Torque (Newton Laws) Lesson 17_02_2025.pptx

AQA AS Moment & Torque lesson along with past paper questions

1. Moments & Torque (Mechanics) A-Level Edexcel Physics | Tutoring Lesson 01 Date: 24/02/2025 Instructor: Muhammad Sameer Sajid

2. Definition of Moments & Torque A MOMENT is the turning effect of a force around a pivot. Formula: Moment (Nm) = Force (N) × Perpendicular Distance (m) TORQUE is a special case of moment, often in rotating systems. SI Unit: Newton-meter (Nm)

3. Diff. B/W Torque & Moment

4. Principle of Moments When an object is in EQUILIBRIUM , the sum of clockwise moments equals the sum of anticlockwise moments. Equation: Used to determine unknown forces in balanced systems.  

5. Applications in Levers & Balancing Objects Types of Levers: First-class (e.g., seesaw, crowbar) Second-class (e.g., wheel - barrow, nutcracker) Third-class (e.g., tweezers, fishing rod) Real-world examples: Using a spanner to tighten bolts Lifting objects using a lever system

6. Problem-Solving Practice Calculate the missing force in a lever system given distances and forces. Determine whether an object is in equilibrium using Identify pivot points and effective distances. Example: A uniform beam is balanced with forces of 10N and 15N at distances 2m and 3m from the pivot. Find the reaction force at the pivot.  

7. Solution

8. Exam-Style Questions (Edexcel) A force of 5N acts at a perpendicular distance of 3m from a pivot. Find the moment. A uniform beam of length 5m is supported at its center. A 10N force acts 2m from the pivot. Find the reaction force at the pivot. A spanner of length 0.25m applies a force of 50N to a nut. Find the torque exerted.

9. Solution