Newton's Laws of Motion Summary

Newton's Laws of Motion: Summary

• Newton's First Law (Inertia): An object remains at rest or in uniform motion in a straight line unless acted upon by a net force.

• Inertia: Resistance to changes in motion; the greater the mass, the greater the inertia.

• Example (Inertia): A coin in a moving airplane; it stays with the plane due to shared velocity.

• Newton's Second Law (Acceleration): The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma).

• Forces and Acceleration: A larger force leads to greater acceleration for constant mass. Increasing the mass reduces acceleration for a constant force.

• Example (Acceleration): Dropping balls with different masses; they reach the ground at the same time (ignoring air resistance) due to equal acceleration from gravity irrespective of mass

• Example (Equilibrium and Acceleration): Skydiving; air resistance counteracts gravity, leading to a terminal velocity. Passengers in a turning vehicle experience an inertia-induced force.

• Newton's Third Law (Action & Reaction): For every action, there is an equal and opposite reaction.

• Equal and Opposite Forces: When one object exerts a force on another, the second object exerts an equal force in the opposite direction.

• Example (Action & Reaction): Firing a cannon; the cannon recoils due to the equal and opposite force from the launched cannonball. Rocket propulsion; exhaust gases push downward, propelling the rocket upward.

• Example (Action & Reaction): A soccer player kicking a ball. The ball exerts an equal force back on the player's foot.

• Different Masses and Effects: The magnitude of the reaction force is the same but the effect differs based on mass. A cannonball will have a more significant effect than the recoil on a cannon.