L03- Newton's Laws of Motion-Learn
Page 1: Biomechanics Overview
Linear Kinetics: Study of forces and motion in biomechanics.
Newton's Laws of Motion: Fundamental principles governing movement.
Gravity: The force that attracts two bodies toward each other.
Page 2: Lecture Outline
Newton’s Laws:
1st Law: Law of Inertia
2nd Law: Law of Acceleration
3rd Law: Law of Action-Reaction
Law of Universal Gravitation
Centre of Mass/Gravity
Page 3: Newton’s Laws of Motion
Kinematics: Motion in terms of time and space (velocity, distance, acceleration).
Kinetics: Forces acting on a body/system and motion production.
Newton’s Contributions: Formulated in his 20s; pivotal for biomechanics and sports.
Sir Isaac Newton: Key figure (1642-1727) in physics and mathematics.
Page 4: Newton’s 1st Law: Law of Inertia
Definition: A body remains at rest or continues with constant velocity unless acted upon by an external force.
Concept of NET force: Important to understand vector components.
Page 5: Newton’s 1st Law: Example
Force Scenarios:
If F1 = F2: No movement
If F1 > F2: Movement in the direction of F1
If F1 < F2: Movement in the direction of F2
Different angles affect direction and magnitude.
Page 6: Applicability in Sports
Long Jump Example: Discusses inertia in a sporting context.
Page 7: Net Force Implications
Rest and Motion: A body at rest stays at rest; a body in motion remains in motion if no net force acts.
Examples: Everyday and sports-related situations.
Page 8: Newton’s 2nd Law: Law of Acceleration
Definition: Acceleration is proportional to the force acting on an object, F = ma.
Units: F (N), m (kg), a (m/sec²).
Newton’s Constant: 1 N accelerates 1 kg at 1 m/sec².
Page 9: Understanding F = ma
Acceleration Calculation: a = F/m; greater mass requires greater force for acceleration.
Force and Acceleration Relationship: Increasing force increases acceleration.
Page 10: Newton’s 3rd Law – Action-Reaction
Definition: Every action has an equal and opposite reaction force.
Significance: Reaction forces are essential to change motion.
Page 11: Implications for Sport
Ground Reaction Forces: Importance of body positioning to maximize these forces.
Page 12: Practical Example in an Elevator
Experiencing Motion: How a biomechanist would notice elevator movement without sight.
Page 13: Forces in Elevator Scenarios
Force Dynamics: Examine forces acting on a person in an elevator and their perceptions.
Page 14: Newton's Law of Gravitation
Gravity Basics: Essential understanding of gravitational forces.
Page 15: Law of Gravitation Formula
Attractive Force: F = G (m1m2)/r²; effects of distance and masses.
Practical Example: Very small forces between small masses.
Page 16: Weight Calculation on Earth
Weight Equation: W = G (mearth × mobject)/r²; results in fixed gravitational acceleration g = 9.81 m/sec².
Page 17: Trivia of the Day
Earth's Gravitational Differences: Discussion on equator vs. poles.
Page 18: Additional Facts
Page 19: Calculating Gravity Above Earth
Gravity at 1000 km: Adjusted calculations based on distance from Earth's center.
Page 20: Inertia in Linear Motion
Definition: Inertia as resistance to motion changes, linked to mass.
Page 21: Weight and Centre of Gravity
Weight Definition: Sum of attractive forces acting towards Earth's center (W = mg).
Centre of Gravity: Resultant force concept central to biomechanics.
Page 22: Centre of Gravity Insights
CG Positioning: Can lie outside physical boundaries; implications for sports.
Page 23: Weight on Moon
Weight Calculation: Changes in weight versus mass on the moon (gravity = 1.57 m/s²).
Page 24: Upcoming Test Reminder
Online Class Test: Details about the formative assessment based on weeks 1-3 content.