Real Size & Orbit of Earth and Moon
The photographs of the Earth and the moon close together that you can see on posters, etc., are designed to be easy to see. The moon’s apparent diameter is only about 0.5˚. This tells us that … more
Precipitation Reaction
A precipitation reaction is a type of reaction when two solutions react to form an insoluble solid (ionic salt) A lot of ionic compounds dissolve in water and exist as individual ions. But when two ions … more
Refraction on water
Refraction is the bending of a wave caused by a change in its speed as it moves from one medium to another. This occurs because of the slow speed of light in dense materials. Examples of … more
Equilibrium
* If the simulation does not move, please refresh the web page. Radiation Places near the stove feel warmer than far away. This is due to the direct transfer of heat from the stove without the … more
Phase array
Spinning radar In general, electromagnetic waves (radio waves) propagate in all directions. In this case, radio waves can be transmitted or received in any direction. However, as the distance increases, the strength of the radio wave … more
Plants Respiration
Plants Respiration Animals carry out active breathing movements to obtain the energy they need for life activities. Through this breathing movement, oxygen is absorbed, and carbon dioxide is released. Like animals, plants do respiration. However, plant … more
Newtonian Reflector
Refracting telescope A telescope that uses only the refraction of a lens is called a refracting telescope. There are two types of refracting telescopes depending on the combination of lenses. The Galilean telescope is often referred … more
Refracting telescope (Keplerian, Galilean)
Refracting telescope A telescope that uses only the refraction of a lens is called a refracting telescope. There are two types of refracting telescopes depending on the combination of lenses. The Galilean telescope is often referred … more
Kinetic Energy
Kinetic energy All moving objects have kinetic energy. The kinetic energy Ek of an object with a mass of ‘m’ and a velocity of ‘v’ can be calculated as follows. \[E_{ k }=\frac { 1 }{ … more
Eratosthenes’ Calculation of Earth’s Circumference 2
Eratosthenes’ Calculation of Earth’s Circumference The first person to measure the earth’s size was Eratosthenes, an ancient Greek scientist about 2,000 years ago. Eratosthenes lived in Alexandria, near the Nile River’s mouth by the Mediterranean coast, … more
Elastic energy
Elastic (potential) energy stored in the spring The elastic energy is stored in the deformed spring. Also called ‘potential energy,’ and denoted by Ep. \[ Elastic \;energy \;E_p(J) = \frac{1}{2}kx^2 \] m: Mass (kg) k: Spring … more
Geocentrism vs. Heliocentrism
Geocentrism, The Geocentric theory The Geocentric theory is a cosmic perspective in which the Earth is at the center, and all the stars revolve around the Earth. From the 13th to the 17th century, it was … more