Circumference of a Circle

Circumference of a Circle

How to find out the circumference of a circle Let’s draw a regular polygon (inscribed polygon and circumscribed polygon) surrounding a circle. The perimeter of an inscribed polygon is less than the perimeter of the circle, … more

Pythagorean Theorem

Pythagorean Theorem

Pythagorean theorem Assuming that the three sides of a right triangle are a, b, c, and the longest side is c, the Pythagorean theorem is that the equation a²+b²=c² is always true. The equation a²+b²=c² represents … more

Flame Test Simulation

Flame Test

* This simulation take the spectral data from NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY. When heat is applied to the atoms, some electrons can have high energy levels and fall to the lower levels. Some electrons … more

Electromagnetic Waves

Electromagnetic Waves

What is light? A form of energy that brightly illuminates the world we live in is called light. Various electromagnetic waves, including visible light, are emitted from hot objects or objects with energy. Visible light is … more

Area of Circle

Area of Circle

How to calculate the area of a circle If you cut the circles and stick them together, they gradually become more rectangular. In this rectangle, the width is half of the circumference, and the height is … more

Doppler Effect and RedShift

Doppler Effect and RedShift

Doppler Effect By listening to the ambulance’s siren, we can tell if the ambulance is coming or going. When an ambulance approaches with a siren, the sound wave’s wavelength becomes shorter (higher note), and when it … more

금성의 위상

Phase of Venus

Venus’ changes in phase and size are strong evidence of ‘Heliocentrism.’ Venus looks like a crescent moon or a full moon, depending on its angle to the sun. Venus is large when it looks like a … more

Young's Double Slit Simulation

Young’s Double Slit

You can adjust the spacing and position of the slits. Young’s double slit experiment Young’s interference experiment is as follows: The light diffracted from the small holes S0 on-screen ‘A’ passes through the small holes S1 … more

Electron Configuration of an Atom

Electron Configuration of an Atom

Orbital An atom has an atomic nucleus with a (+) charge at the center and electrons with a negative charge around it. Electrons are arranged according to certain rules (wave functions), which are called ‘orbitals.’ In … more

Magnetic Field around a Bar Magnet

Magnetic Field around a Bar Magnet

Magnetic field around magnet The space where the magnetic force of the magnet acts is called a ‘magnetic field.’ The direction of the magnetic field is determined in the direction indicated by the N pole of … more

Resonance

Resonance

Resonance Resonance is a phenomenon in which the amplitude increases at a specific frequency. The resonance phenomenon can be easily observed around us. 1. Swing When you push the swing, if you push it well according … more

Superposition Simulation

Superposition

Superposition and interference of waves Two matters cannot be in the same location. But, two or more waves can be in the same space and at the same time. Throwing two stones into the pond creates … more