In this article, physical quantities related to the motion of a parachute system in the framework of Newton's law of mechanics guide an informal approach to the mathematical concept of function. Furthermore, a graphical simulator that enables visualization of the fall of object-parachutes system is presented. The article is aimed at students and…

Presented are the background theory, program procedures, output display, and applications for this program which is designed to calculate the slip vector and the stress to normal stress ratio on an arbitrarily oriented fault plane. Program availability is discussed. Twelve references are listed. (CW)

This document contains an instructional unit which deals with one major topic in ecology. It focuses on the variables which affect the development of populations and determine their final size within a given period of time. The variables operating in nature which determine the development of populations are numerous, thus complicating the task of…