Newtons 1st Law of Motion

Definition

Every body persists in its state of rest or uniform motion in a straight line, unless compelled to change that motion by forces impressed upon it

What does this law Intail ?

How objects behave when no forces are present, they continue doing what they were doing

Sometimes called the …

Law of inertia

Definition of Inertia

The tendency for an object to resist changes in motion

What is the relashionship between and objects Mass and its Inertia

Congruent, the more mass an object has, the more inertia it has. Any given mass will resist a bigger change in motion than a smaller one

Any given mass will,

Resist a bigger change in motion more than a smaller one

The resistance of an object offer to changes in motiin depends upon two things

The amount of Inertia present (m) and the size of the change in motion

What are some examples of Inertia

Ripping a piece of paper towel, tightening a hammer head, pulling a table cloth out from under a fine china

Definition of Mass

The measure of the amount of matter in an object

Definition of Weight

The force of graviry acting on mass

Weight is proportional to ….

Mass

What is the formula for finding weight when mass (kg) is known ?

W=mg

What are the two ways of measuring mass

Using weight (equal arm balance), Using inertia (inertial balance)

What is a spring scale, and what should it be labeled as ?

A tool used to measure force, it has a scale marked off as grams because of the formula W=mg, therefore it should have the lable “for earth use only”

Definition of Volume

The measure of the amount of space in an object

What is the Unit of Volume ?

cm³ (=mL), dm³ (=L), m³, etc

Is volume proportional to mass ?

Not usually true, materials have different densities, only true if they are made out of the same material

Equations for Volume

d=m/V m=dV