admin.official Permutations and combinations are two important ideas in mathematics that help us count the number of possible ways to arrange or select objects. Combination Combination is used when order does not matter.For example, choosing 2 ice-cream flavors from 5.Chocolate + Vanilla is the same as Vanilla + Chocolate, so it is counted only once. Formula … 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
Humans can hear sounds in the frequency range of about 20 Hz (very low bass) to 20,000 Hz (very high pitch). Younger people—especially children—can usually hear higher frequencies than adults, and as we grow older, our ability to hear the highest pitches naturally decreases. The Human Hearing Range Explorer is a fun and interactive tool … 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
This fun and interactive widget lets kids explore the world of sound by creating their very own sound waves! They can choose from four wave types—sine, square, triangle and saw tooth—each with its own unique sound and matching colorful animation. Using simple sliders, kids can adjust the frequency (how high or low the pitch of … 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 it? How Sound Waves are formed? Let’s take a simple example. Throw a stone in … Read more
Binoculars are interesting devices that helps us in viewing distant objects with some level of magnification. It can be used for many things such as sporting events, star gazing, bird watching along with many different natural views. How it works? The below diagram shows the construction of a typical binocular: In order to understand the … Read more