My acknowledgement starts with the authors of the famous undergraduate physics text book namely Fundamentals of Physics (10th Ed.) by R. Resnick, D. Halliday and J. Walker. We had also this book as our text book during our undergraduate degree back in 1973-1976. I believe Jearl Walker was not one of the authors during that period. I am taking the technological advantages to compose my electronic books using the incredible and prolific tools developed by Yihui Xie [https://twitter.com/xieyihui] which transforms R Markdown documents into a book. I am grateful to Yihui Xie for making the “Authoring Books and Technical Documents with R Markdown” available to us.