1 The Fission Theory: The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. 2  The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came.
In our Tire Talk forum, some of our readers have questioned the interchangeability of P-metric and Metric tire size designations. But answering this question is like asking how to solve the national debt crisis. In other words, there are many answers, and some might be more practical solutions than others. There are two major size designations commonly used for passenger car tires, called P-metric and Metric sizing. If you see a âPâ in front of the tire size displayed on a tireâs sidewall it is a P-metric tire. If thereâs no P, itâs a Metric tire (also called Euro-metric or Hard-Metric).
Imperial vs. Metric System. There are two main systems for measuring distances and weight, the Imperial System of Measurement and the Metric System of Measurement. Most countries use the Metric System, which uses the measuring units such as meters and grams and adds prefixes like kilo, milli and centi to count orders of magnitude. In the United States, we use the older Imperial system, where things are measured in feet, inches and pounds. It might be confusing if you are living in the U.S for the first time and are not used to this system.