Newton’s First Law of Motion
Newton’s First Law of Motion, also known as the Law of Inertia, states: “An object at rest will remain at rest, and an object in motion will continue in motion with a constant velocity, unless acted upon by an external force.”
Key Concepts:
- Inertia: The property of an object to resist changes to its state of motion.
- Force: An external influence that can change the state of motion of an object.
Examples:
- A book on a table remains at rest until pushed.
- A car moving at a constant speed will continue moving unless acted upon by a force (e.g., friction, braking).
Newton’s Second Law of Motion
Newton’s Second Law of Motion states: “The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass.”
Formula:
\( F = m \cdot a \)
Key Points:
- Force and acceleration are directly proportional.
- Force and mass are directly proportional.
- Acceleration and mass are inversely proportional.
Newton’s Third Law of Motion
Newton’s Third Law of Motion states: “For every action, there is an equal and opposite reaction.”
Examples:
- Recoil of a gun: The bullet moves forward, and the gun moves backward.
- Walking: Your foot pushes backward on the ground, and the ground pushes your foot forward.
Related Concepts
Linear Momentum
Linear momentum is the product of an object’s mass and velocity. It is a vector quantity with both magnitude and direction. The formula is:
\( p = m \cdot v \)
Relative Motion
Relative motion refers to the motion of an object as observed from a particular frame of reference. The perceived motion can vary based on the observer’s position and movement.
Absolute Motion
Absolute motion refers to the theoretical concept of an object moving in a fixed, universal frame of reference. In practical terms, all motion is relative.