In the past I thought for instance the BOOK ON THE TABLE had only 1 force, and that force was gravity. I couldn’t see that something that wasn’t living could push back. I thought that this push back force wasn’t a real force but just an in the way force or an outside influence on the book.
However, my ideas have changed since the beginning of this year. Sr. Hennessey helped me to see the difference between the macroscopic level and the microscopic level. That was last year. But I never really thought about the difference very much.
This year, I began to think about the book on the table differently than [last school year] I was thinking on the macroscopic level and not on the microscopic level. This year I wasn’t looking at the table from the same perspective as last year. Last year I was looking at living beings as the important focus and now I am looking at the molecules as being the important focus. When I finally got my thoughts worked out, I could see things from a different perspective. I found out that I had no trouble thinking about two balanced forces instead of just gravity working on the book. It took me a whole YEAR to figure this concept out!!! Now I know it was worth THE YEAR to figure it out because now I can see balanced forces everywhere!
Balanced forces are needed to produce constant velocity. The book on the table has a velocity of zero; that means it has a steady pace of zero. Why, Sr. Hennessey asked, did my ideas change? I think my ideas changed because I have expanded my mind to more complicated ideas! Like molecules in a table can have an effect on a book, that balanced forces and unbalanced forces are a better way of explaining the cause of motion, and that constant velocity and changing velocity are important things to look at when describing motion.