In this text I've used the SI most, particularly toward the end of the book. I interject the other two systems to familiarize you with one of life's hard realities and to force your awareness of units as you solve problems. In the end you will have a better mastery of SI than you would if all problems had used those units just as you have a better understanding of English after you've learned a second or third language. Write the units of pressure anad density in the cgs system. I hope you have noticed the different use of units and dimensions .
Dimension refers to the type of measurement, such as length.
Unit refers to the particular standard , such as centimeter, foot, meter, or Angstrom. Think up a meaningful physical quantity for each of the following and state what unit system it is in. Write the unit that corresponds to the one given, but in the system stated.