Basically, I think this book, “Physics for Future Presidents” is more like an enlightening reading matter after roughly going through the section one, but it was fun to have a contact with those numbers in the book. I can feel the strong theoretical support of physics from reading between lines. For example, I really didn’t know that the World Trade Center was destroyed by the jet fuel in the airplane’s tank. From an early age, I always thought that the World Trade Center was damaged by a plane crash. After all, the plane was so big that it sounded like a monster every time it was started. To ensure the data is correct, I calculated the numbers myself. So, the plane weighed 131 tons which is equivalent to about 119,000 kilograms, and I used US ton here because the following velocity unit was also in US system. For the velocity of the plane, 600 miles per hour roughly equals to 300 meters per second which is amazingly high. As we all know, the speed of the sound is approximately 340 meters per second, and that indicates how fast the plane was when it was about to hit The World Trade Center. From the calculation, I got 5*10^9 Joules which is about 1 metric ton of TNT’s energy. To be honest, it was amazing for me to get such a huge number when I also learned the total amount of energy released was about 1800 tons of TNT, and that means the fire and explosions caused by the jet fuel were the main reason how the World Trade Center was cut in half from the middle. Although I haven’t properly learned an equation for calculating the heat energy and other energies released by the jet fuel, I am looking forward to learning it and come back to verify the numbers.