A sensor that is commonly used is the electromechanical design of a "gas dampened tube and ball." It is a sensor with nothing else but a tube that is small with a small switch at one of the ends and a steel ball that is gold at the other end. Its all held together by a magnet. If and when it receives a jolt that is hard enough, it can knock the magnet and loosen the ball and makes it roll down the tube and hit the switch to close the circuit. It will return to its original place because of the slanted design of the tube.
One of the most commonly used sensors is the electromechanical "ball and tube" design. The ball and tube design uses a sensor that activates a small metal ball whenever it receives a hard enough jolt from it's magnet. Whenever it does, it's gold plated ball rolls down the tube and hits a small switch which then closes the circuit that it is connected to. If you want to reset the ball and tube, just tilt the tube to the other side and the ball will go back to its original position.
You need to write the main idea of each paragraph of the story and if all the mean ideas are about the same topic then you got the main or central idea of the story.
He discover that he might suffer from some mental disorder causing him to react aggressively and with no limits at all,suffering afterwards from the aftermath of his own actions therefore he decides to keep a journal about it for research....
