Hoang Lihuo

The modern picture of an atom is a nucleus which is very small compared to the size of the atom.And if the atom is neutral the number of electrons and the number of protons is the same.If you take electron off you get a positive ion.If you add an elentron then you get a negative ion. The charge of the electron is the same as the charge of the proton.That's why the number is the same for neutral  atoms.  Electrostatics deals with forces between charges .  Static means the charges are not moving, or at least a re not moving very fast.  How fast is "not very fast"?   When a charge moves, it generates a magnetic field, which can lead to a magnetic force. As we begin our study of electricity, we want to minimize complexity and focus just on electric force. To keep things simple, we let charges stand still, or move very slowly. So "not very fast" means motion so slow the magnetic effects are insignificant compared to the electric forces....

In this example, We will read the sensor analog output voltage and when the smoke reaches a certain level, it will make sound a buzzer and a red LED will turn on. When the output voltage is below  that level, a green LED will be on. What is an MQ-2 Smoke Sensor? The MQ-2 smoke sensor is sensitive to smoke and to the following flammable gases: LPG Butane Propane Methane Alcohol Hydrogen The resistance of the sensor is different depending on the type of the gas. The smoke sensor has a built-in potentiometer that allows you to adjust the sensor sensitivity according to how accurate you want to detect gas. How does it Work? The voltage that the sensor outputs changes accordingly to the smoke/gas level that exists in the atmosphere. The sensor outputs a voltage that is proportional to the concentration of smoke/gas. In other words, the relationship between voltage and gas concentration is the following: The greater the gas concentration, the g...

Arduino is an open source computer hardware and software company, project, and user community that designs and manufactures single-board microcontrollers and microcontroller kits for building digital devices and interactive objects that can sense and control objects in the physical world. A program for Arduino hardware may be written in any programming language with compilers that produce binary machine code for the target processor. Atmel provides a development environment for their 8-bit AVR and 32-bit ARM Cortex-M based microcontrollers: AVR Studio (older) and Atmel Studio (newer). IDE The Arduino integrated development environment (IDE) is a cross-platform application (for Windows, macOS, Linux) that is written in the programming language Java. It originated from the IDE for the languages Processing and Wiring . It includes a code editor with features such as text cutting and pasting, searching and replacing text, automatic indenting, brace matching, and syntax highl...

Class Teedcalculator: /*  * To change this license header, choose License Headers in Project Properties.  * To change this template file, choose Tools | Templates  * and open the template in the editor.  */ package teedcalculator; import static teedcalculator.Oparetor.tand;// to access all static Tand of a class import static teedcalculator.Oparetor.tan;// to access all static Tan of a class import static teedcalculator.Oparetor.cost;// to access all static Cost of a class import static teedcalculator.Oparetor.cosd;// to access all static Cosd of a class import static teedcalculator.Oparetor.degree2;// to access all static Degree of a class import static teedcalculator.Oparetor.divide;// to access all static divide of a class import static teedcalculator.Oparetor.minus;// to access all static minus of a class import static teedcalculator.Oparetor.modulo;// to access all static modulo of a class import static teedcalculator.Oparetor.multiply;// to acce...