Cutting

Cutting is the separation of a physical object, into two or more portions, through the application of an acutely directed force.

Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel and microtome. However, any sufficiently sharp object is capable of cutting if it has a hardness sufficiently larger than the object being cut, and if it is applied with sufficient force. Even liquids can be used to cut things when applied with sufficient force (see water jet cutter).

How it works

Cutting is a compressive and shearing phenomenon, and occurs only when the total stress generated by the cutting implement exceeds the ultimate strength of the material of the object being cut. The simplest applicable equation is stress = force/area: The stress generated by a cutting implement is directly proportional to the force with which it is applied, and inversely proportional to the area of contact. Hence, the smaller the area (i.e., the sharper the cutting implement), the less force is needed to cut something. It is generally seen that cutting edges are thinner for cutting soft materials and thicker for harder materials. This progression is seen from kitchen knife, to cleaver, to axe, and is a balance between the easy cutting action of a thin blade vs strength and edge durability of a thicker blade.

Phil McGraw

Phillip Calvin "Phil" McGraw (born September 1, 1950), known as Dr. Phil, is an American television personality, author, psychologist, and the host of the television show Dr. Phil, which debuted in 2002. McGraw first gained celebrity status with appearances on The Oprah Winfrey Show in the late 1990s. In 2015, Forbes listed his earnings at $70 million for the previous 12 months, and ranked him the 15th highest earning celebrity in the world.

Early life

McGraw was born in Vinita, Oklahoma, the son of Anne Geraldine "Jerry" (née Stevens) and Joseph J. "Joe" McGraw, Jr. He grew up with two older sisters, Deana and Donna, and younger sister Brenda in the oilfields of North Texas where his father was an equipment supplier. During McGraw's childhood, his family moved so his father could pursue a lifelong goal of becoming a psychologist.

McGraw attended Shawnee Mission North High School in Overland Park, Kansas. In 1968, he was awarded a football scholarship to the University of Tulsa, where he played middle linebacker under Coach Glenn Dobbs. On November 23 of that year, McGraw's team lost to the University of Houston 100–6, which is one of the most lopsided games in college football history. Coach Dobbs retired after that season and McGraw transferred to Midwestern State University in Wichita Falls, Texas.