Physics Flashcards - Newton's Laws of Motion

Nat's Year 10 Science - Physics

Newton’s First Law of Motion

An object at rest will remain at rest unless it is acted upon by a force. An object that is moving will continue to move at the same speed and in the same direction unless acted on by a force.

Inertia

An object’s ability to resist a change in motion. Large, heavy objects are very resistant to movement, therefore they have a lot of inertia.

Inertia - Impact on objects

The tendency of an object to keep moving in the same direction and at the same speed that it was initially. An object will not change its speed or direction, unless acted upon by a force. It depends on the mass of the object. Greater mass = greater inertia

Examples of Inertia

Net Force

The sum of the forces acting on a single object is called the net force. To find the net force , add any force acting in the same direction and subtract any forces acting in the opposite directions.

Balanced Net Force

Net Force = 0

Unbalanced Net Force

Net Force = (?) in a particular direction

Newton’s Second Law of Motion

Describes the relationship between force, mass and acceleration of an object. Force (Newtons (N)) = Mass (kg) x Acceleration(ms^-2). Also known as F = ma. More force = faster acceleration and heavier = slower acceleration.

Newton’s Third Law of Motion

For every action, there is an equal and opposite reaction. When an object applies force to another object, the second object exerts an equal force back on the first object.

Examples of Newton’s Third Law of Motion

Normal Force

A force that is perpendicular to the surface that an object contacts. It is always acting upwards or outwards (90 degrees to the surface). It’s a reaction force and balances the action force.