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).
As distance is to displacement, so speed is to velocity: the crucial difference between the two is that speed is a scalar and velocity is a vector quantity. In everyday conversation, we usually say speed when we talk about how fast something is moving.