Derived quantity

Definition

A derived quantity is a physical quantity that is defined in terms of base quantities through multiplication or division. Examples include velocity, acceleration, and force.

5 Must Know Facts For Your Next Test

1. Derived quantities are expressed using combinations of base units, such as meters per second (m/s) for velocity.
2. The dimensional formula for a derived quantity is obtained by combining the dimensional formulas of its constituent base quantities.
3. Common derived quantities in mechanics include speed ($\text{LT}^{-1}$), force ($\text{MLT}^{-2}$), and work ($\text{ML}^{2}\text{T}^{-2}$).
4. Derived units can be complex, involving multiple base units, such as the newton (N) which is equivalent to $\text{kg} \cdot \text{m/s}^2$.
5. Understanding derived quantities is essential for solving problems in physics as they describe relationships between different physical phenomena.

Review Questions

• What are the base units involved in the derived unit for force?
• How do you obtain the dimensional formula of a derived quantity?
• Give an example of a derived quantity and its corresponding SI unit.

Related terms

Base Quantity: Fundamental physical quantities from which other quantities are derived, such as length (meter), mass (kilogram), and time (second).

Dimensional Analysis: A method used to convert one kind of unit to another and to check the consistency of equations involving physical quantities by comparing their dimensions.

SI Units: (International System of Units) The globally accepted metric system used for scientific measurements, including seven base units like meter, kilogram, and second.