The density of the blade is constant throughout its length, and so a 10%-mass. fragment will have a cross-sectional area of 10% of the full blade. In practice, the. area of a 10%-mass fragment will vary depending upon its shape, and upon whether. it consists of the only the outer shell or the internal beams as well.
Alcohol is the most commonly used and abused drug among youth in the United States.1. 1  Excessive drinking is responsible for more than 4,300 deaths among underage youth each year, and cost the U.S. $24 billion in economic costs in 2010.2,3.
(Early Use of Marijuana) The younger and more often teens use marijuana, the more likely they are to engage in other substance use and the higher their risk of developing a substance use disorder. Among high school students, 7.5 percent used marijuana for the first time before the age of 13.Non-Recreational Adolescent Marijuana Use) The findings of this study provide one of the first in-depth descriptions of youths' use of marijuana for non-recreational purposes, adding to the growing body of research on the use of drugs to self-medicate among young people.