1.1. The Big Idea http://www.ck12.org
1.1 The Big Idea
Since physics depends fundamentally on measurements that are interpreted through math, the first distinction we
have to make is between different types of measurements and their properties. First, all measurements must have
units. Units identify what a specific number refers to. For instance, the number 42 can be used to represent 42 miles,
42 pounds, or 42 elephants! Numbers are mathematical objects, but units give them physical meaning. Keeping
track of units can help you avoid mistakes when you work out problems.