# Science, Technology, Engineering, and Mathematics (STEM)

Electronics Lab
Even though an electronic circuit may appear to work on paper, and maybe even in a circuit simulator, it's always important to test it in the real world. Prototype circuits can be built using a solderless breadboard. More ...

Use a Resistor to Measure Inductance
Inductance is usually measured by using an LCM multimeter. It can also be mesured using a resistor. With the resistor method, you adjust the frequency of a sine wave until the AC voltage accross the resistor and inductor are equal. Then using a formula to calculate the inductance. More ...

Direct Current
The nucleus of an atom is relatively heavy, so electricity primarily involves the flow of electrons. The nucleus of an atom generally doesn't move much. More ...

How to Observe Constellations
Observing the constellations makes for a great hobby that can even lead to a career as an astronomer or to another space-related career. This article provides some of the basics for finding constellations. More ...

How to Learn Algebra
One of the trickiest things about solving an algebra equation as a beginner is knowing where to start. There's a specific order for solving algebra problems: first do any math operations in parentheses, then do exponents, then multiply, then divide, then add, and finally subtract. More ...

Average Velocity and Instantaneous Velocity
If a particle moves from one point to another, we might need to know how fast it moves. We can define two quantities that deal with how fast, average velocity and instantaneous velocity. Here we consider these quantities as vectors and use vector notation. More ...

Properties of Algebra
In this article you learn how to simplify algebraic expressions by substituting given values, distributing, and combining like terms. More ...

Force and Mass
From everyday experience you know that applying a given force to bodies (say, a baseball and a bowling ball) results in different accelerations. The explanation is that the object with the larger mass is accelerated less. More ...

Introduction to Angles: Acute, Obtuse, Straight, and Right
An angle is the amount of turn between two lines around thethe vertex. The name of an angle uses an angle symbol followed by three letters. The letter from one side, the letter from the other side, and the letter of the vertex. The letter of the vertex must go in the middle. More ...

Mathematics Factoring Basics
Factoring is very important in algebra because it allows us to perform operations on fractions with different denominators, write polynomials in a simpler form, and make many calculations a lot simpler. This article explains the very basics of factoring. More ...

Projectile Motion
In projectile motion, a particle is launched into the air with a speed v and at an angle theta (as measured from a horizontal x axis). More ...

Inductive Reactance
The opposition that the coil offers to ac is called inductive reactance. Like resistance, reactance is measured in ohms. Unlike resistance, reactance changes with frequency. And in an Inductor, the Voltage leads the Current by 90 degrees. More ...

The Normal Force
The Normal force is the force that acts in perpendicular direction to the surface that an object contact. Friction is a force that opposes the relative motion between systems in contact. The magnitude of the friction force is directly proportional to the normal force. More ...

Triac
You can of a triac as two back-to-back SCRs with the cathode of one SCR connected to the anode of the other. The gates are connected together. Because we have a two SCRs configuration you can control the switching of both half cycles. More ... 