admin.official 
Have you ever seen tiny balls falling through a triangle of pegs and collecting in bins at the bottom, forming a perfect bell-shaped curve? That fascinating device is called a Galton Board — also known as a Quincunx or Bean Machine. Invented by Sir Francis Galton in the 19th century, this clever machine offers a … Read more
This permutations versus combinations interactive tool helps students count selections, arrangements, and possibilities. Explore exactly how the answer changes when order matters or does not matter. How to use the permutations versus combinations interactive tool Choose the total number of objects, choose how many will be picked, then compare the two counting methods. 1 Choose … Read more
What is a hand water pump? A hand water pump is simple device that pulls water up from underground. It uses mechanical motion of hands to pull the water from the underground. It has a long handle that you move up and down. When you do this, it uses air pressure and valves to pull … Read more
Balloons moving up in the air always fascinate us as children. But have you wonder why they move up in the air? The underlying principal for balloons upward movement is the same as that of objects floating on water. The balloon moves in the upward direction due to difference in the densities of the … Read more
Explore the human hearing range from low bass to very high frequencies, compare pitch and period, and optionally record observations from short quiet tone bursts. How to use the human hearing range explorer 1 Lower your volume Set your device volume very low before playing a tone. Stop immediately if any sound feels uncomfortable. 2 … Read more
What is a mirage? A mirage is a naturally occurring optical illusion that occurs when light bends due to temperature differences in the air and result in making objects appear to be in different location than they are. Sometimes, it also creates a view of a pool of water or a distorted reflection on the … Read more
Enter any two known parameters such as mass and volume, volume and density or mass and density to find the third unknown parameter Density Calculator Density (g/cm³): Mass (g): Volume (cm³): Calculate
Do you know what do cameras, eye glasses, telescopes and microscopes have in common? The object at the core of these devices is an optical lens. A lens is a transparent object and light is refracted when it passes through the lens. Lens is used in many optical instruments such as cameras, microscope, telescope, optical … Read more
Make your own sound wave by choosing a waveform, changing its frequency and amplitude, observing the shape, and optionally listening to the resulting tone. How to make your own sound wave The visualizer opens silently. You can explore every control and waveform before starting the audio. 1 Choose a wave shape Select sine, square, triangle, … Read more
In our daily life, we hear a lot of different sounds; sound of other people, sound of car, sound of water flowing, sound of different animals etc. Have you ever wonder how sound is generated and how do we hear the sound waves? How Sound Waves are formed? Let’s take a simple example. Throw a … Read more