Magnitudes Físicas | Fundamentales y derivadas | Escalares y vectoriales

Understanding Physical Magnitudes

Definition of Magnitudes

• A magnitude is anything that can be measured, such as water temperature with a thermometer or a person's mass with a scale. Measuring involves comparing one magnitude to another of the same kind, known as a standard or pattern.

Types of Physical Magnitudes

Fundamental and Derived Magnitudes

• Physical magnitudes are categorized into two types: fundamental and derived.

• Fundamental Magnitudes include:

• Length (measured in meters)

• Mass (measured in kilograms)

• Time (measured in seconds)

• Temperature (measured in Kelvin)

• Electric current intensity (measured in Amperes)

• Amount of substance (measured in moles)

• Luminous intensity (measured in candelas)

These units correspond to the International System of Units. It's crucial to know these for exams.

• Derived Magnitudes are formed from combinations of fundamental magnitudes:

• Examples include:

• Velocity (meters per second)

• Acceleration (meters per second squared)

• Force (Newtons, which is kg·m/s²)

• Work (Joules, derived from Newtons and meters)

• Power (Watts, derived from Joules per second)

• Pressure (Pascals, derived from Newtons per square meter)

• Density (kilograms per cubic meter)

Scalar vs Vectorial Magnitudes

Scalar Magnitudes

• Scalar magnitudes consist of only a quantity and unit; they lack direction or sense. Examples include:

• Distance

• Mass

• Volume

• Time

• Speed

• Temperature

These examples are essential for exam preparation.

Vectorial Magnitudes

• Vectorial magnitudes have both magnitude and direction expressed by an angle; their direction is indicated by the arrow's tip according to compass directions. Examples include:

• Velocity

• Acceleration

• Displacement

• Force

These concepts highlight the importance of understanding both scalar and vectorial properties in physics.