## BIG IDEAS - Matter has properties which can be measured, such as length and mass. - **Physical quantity** is the feature or characteristic of an object that can be measured or calculated. - The value of a physical quantity means comparing the feature to an assigned **unit** (chosen standard) - The quantity is expressed as an algebraic multiplication of the numeric value and a standard (the number and unit). - For example, the length of an object is expressed in meters, the mass of an object is expressed in kg. Here’s a table students should memorize. | | | | |---|---|---| |**Physical Quantity**|**Abbreviation**|**SI unit**| |Length|[L]|meter (m)| |Mass|[M]|kilogram (kg)| |Time|[T]|time (s)| - The dimension of the physical quantity is shown in the table above. - Dimensions can be identified by the square brackets, with the dimensions in a capital letter. - Other physical quantities that you might use in physics include velocity, acceleration, weight, and energy. - There are seven base physical quantities that are recorded by their base SI unit. - A property of an [[Object|object]] that can be measured. A physical quantity may be [[Scalars|scalar]] or [[Vectors|vector]]. <font color="#f79646">Examples of fundamental quantities:</font> - [[Mass|mass]] - [[Length|length]] - [[Time|time]] <font color="#f79646">Quantities may be algebraically combined to form derived quantities. </font> Examples of derived quantities: - [[newton]] - [[joule]] --- Return [[Home|Home]] | [[SI units]] | [[Base Units]]