we are able to show the impact of introducing additional of a variable source, say labor, to a set volume of cash and find out what occurs to output. For demonstration needs in economics, we frequently make widgets, https://www.youtube.com/watch?v=-nQTR6bXhfU&list=PLZ3DkIWtVYetfvXsAvY04--yisQJg2WWI&index=9&pp=iAQB