Notes on Forces and Newton's Laws of Motion

Flashcards about balanced and unbalanced forces, and Newton's Laws of Motion.

What is a force?

A force is a push or a pull that can change an object's motion.

What is the standard unit of force?

The standard unit of force is the Newton (N).

What is Newton's First Law of Motion (The Law of Inertia)?

An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

What is inertia?

Particles are lazy and won’t move unless forced to by an unbalanced force.

What are Balanced Forces?

Forces act in opposite directions but are equal, resulting in no motion.

What are Unbalanced Forces?

Forces act in different directions and are NOT equal, causing the object to move.

What is Newton's Second Law of Motion?

The acceleration of an object is proportional to the force acting on the object, and inversely proportional to its mass.

What is the formula for Newton's Second Law of Motion?

F = ma

What is mass?

The amount of matter within a material, measured in grams, kilograms, tonnes, etc.

What is weight?

A measure of the mass of an object multiplied by gravity, measured in Newtons.

What is Newton's Third Law of Motion?

For every action there is an equal and opposite reaction.

What is the formula for Newton's Third Law of Motion?

F1 = -F2

What is the Normal Force?

The force that surfaces exert to prevent solid objects from passing through each other, always acting perpendicular to the surface.

How does a spacecraft use Newton's Third Law for motion?

When the rocket burns fuel it pushes hot, expanding gases to the rear of the rocket In response, the exhaust gases push the rocket forward with a force called thrust. This is an example of Newton’s Third Law