Infrared Radiations

Infrared (IR) light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres (µm), and extending conventionally to 300 µm. These wavelengths correspond to a frequency range of approximately 1 to 400 THz, and include most of the thermal radiation emitted by objects near room...

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Rainbow

When Sunlight falls on small water droplets suspended in air during or after a rain, it suffers refraction, Total Internal Reflection(TIR) and dispersion. If an observer has the Sun at the back and water droplets in front of himself, then the person may see two rainbows one inside the other. The inner one is called primary rainbow and the outer one is called the secondary rainbow. A ray of light when passing from air to water suffers refraction,...

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How to Spot Venus and Jupiter

Venus (on the left) and Jupiter in the evening sky in 2008. This week their positions will be reversed.   After the moon, they are the two brightest objects in the night sky, and for the next few evenings they will appear side-by-side in western skies in a dazzling heavenly spectacle. Though Jupiter is seven times farther from Earth than Venus, the planets' orbits bring them into close approach on Tuesday...

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Radio Waves

Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves...

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Electromagnetic Radiations

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. The electromagnetic spectrum extends from low frequencies used for modern radio communication to gamma radiation at the short-wavelength (high-frequency)...

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Newton's Laws of motion

Newton's laws of motion are three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces. They have been expressed in several different ways over nearly three centuries, and can be summarized as follows: First law: Every body persists in its state of being at rest or of moving uniformly straight...

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Cohesive and Adhesive Forces

Cohesion: Cohesion or cohesive attraction or cohesive force is the action or property of like molecules sticking together, being mutually attractive. This is an intrinsic property of a substance that is caused by the shape and structure of its molecules which makes the distribution of orbiting electrons irregular when molecules get close to one another, creating electrical attraction that...

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