we can easily demonstrate the affect of incorporating more of a variable useful resource, say labor, to a fixed level of funds and find out what comes about to output. For demonstration needs in economics, we often make https://www.youtube.com/watch?v=-nQTR6bXhfU&list=PLZ3DkIWtVYetfvXsAvY04--yisQJg2WWI&index=9&pp=iAQB