Conversion factors are derived from the relationship between different units of measurement.
They are often expressed as fractions, where the numerator and denominator are equivalent quantities in different units.
The choice of which unit to place in the numerator or denominator depends on the direction of the conversion.
Multiplying by a conversion factor allows you to cancel out unwanted units and introduce desired ones.
$$1 \text{ inch} = 2.54 \text{ centimeters}$$ is an example of a common conversion factor in physics.
Review Questions
What is a conversion factor and how is it used?
Why is it important that the numerator and denominator of a conversion factor represent equivalent quantities?
Provide an example of a conversion factor between metric and imperial units.
Related terms
Unit: A standard quantity used to specify measurements.
Dimensional Analysis: A method that uses units as algebraic quantities that can be multiplied, divided, and canceled out to solve problems involving physical quantities.
Physical Quantity: Any property that can be measured and described with numbers and units.