Newton’s Cradle.

Newton’s cradle, named after Sir Isaac Newton, is a device that demonstrates conservation of momentum and energy via a series of swinging spheres. When one on the end is lifted and released, it strikes the stationary spheres; a force is transmitted through the stationary spheres and pushes the last one upward.

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Taming the sound from a Shuttle using water.

What purpose would a water tank have in the proximity of a space shuttle launch? 

Well, believe it or not, it is used to suppress the acoustical energy (sound and rocket exhaust reflected from the flame trench and Mobile Launcher Platform during launch.

Underlying Principle.

NASA came up with an ingenious way to suppress the sound- Bubbles!

Bubbles are excellent at absorbing the sound. They absorb the sound energy and as a consequence of which get heated up. NASA exploited this and sprayed water molecules in the air surrounding the Mobile Launcher Platform. This reduced the sound from the firing of the rockets by almost a half!

The Sound Suppression System.

The Sound Suppression System includes an elevated water tank with a capacity of 300,000 gallons (1,135,620 liters). The tank is 290 feet (88 meters) high and is located adjacent to each pad. 

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The water releases just prior to the ignition of the Shuttle engines, and flows through 7-foot-diameter (2.1-meter) pipes for about 20 seconds. Water pours from 16 nozzles atop the flame deflectors and from outlets in the main engines exhaust hole in the Mobile Launcher Platform, starting at T minus 6.6 seconds. 

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A rainbird nozzle in action

By the time the solid rocket boosters ignite, a torrent of water will be flowing onto the Mobile Launcher Platform from six large quench nozzles, or “rainbirds,” mounted on its surface. 

The peak rate of flow from all sources is 900,000 gallons (3,406,860 liters) of water per minute at 9 seconds after liftoff.

Exquisite, isn’t it? 

PC: NASA.

Velocity has Vectors!

This breathtaking demonstration shows in an elegant way the independence of the horizontal and vertical components of the velocity vector. 

As you can observe, the horizontal push is by no means interfering with the vertical motion ( the backflip ). The guy still completes his backflip, but the push along the horizontal direction is translating him along that direction!

via reddit.

Celestial Wonders- Binary Stars.

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The twins of the stellar world are binary star systems.A binary star is a star system consisting of two stars orbiting around their common center of mass.When two stars appear close together in the sky, the situation is known as an “optical double”. This means that although the stars are aligned along the same line of sight, they may be at completely different distances from us. This occurs in constellations; however, two stars in the same constellation can also be part of a binary system.

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Artist’s impression of the sight from a (hypothetical) moon of planet HD 188753 Ab (upper left), which orbits a triple star system( yes, a Triple Star system!). The brightest companion is just below the horizon.

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Binary star systems are very important in astrophysics because calculations of their orbits allow the masses of their component stars to be directly determined, which in turn allows other stellar parameters, such as radius and density, to be indirectly estimated. This also determines an empirical mass-luminosity relationship (MLR) from which the masses of single stars can be estimated.

It is estimated that approximately 1/3 of the star systems in the Milky Way are binary or multiple, with the remaining 2/3 consisting of single stars.

The Brightest star in the sky is a binary.

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This is true. When it was discovered in 1844 by the German astronomer Bessel, the system was classed as an astrometric binary, because the companion star, Sirius B, was too faint to be seen. Bessel, who was also a mathematician, determined by calculations that Sirius B existed after observing that the proper of Sirius A (the main star) followed a wavy path in the sky, rather than a uniform path. Sirius can now be studied as a visual binary because, with improving technology and therefore improved telescopes, Sirius B was able to be seen, although not for 20 years after Bessel had correctly predicted its existence.

Black Holes in a binary System ?

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The term “binary system” is not used exclusively for star systems, but also for planets, asteroids, and galaxies which rotate around a common center of gravity. However, this is not a trick question; even in star binaries, the companion can be a black hole. An example of this is Cygnus X-1.

The universe is pretty amazing huh?…

Bullet leaving barrel at 1 million frames per second.

The velocity with which the bullet exits is known as muzzle velocity. It is around 1000 m/s on average. But higher muzzle velocity is also acheivable.

Why don’t rain drops kill you?

Pardon me for being melodramatic. Think about it, rain drops fall from thousands of feet in the air and yet we hardly twitch when one falls on us.This defies all logic, if you drop a penny from the top of a building and let it fall on you, we know that it hurts!
Have the angels cast a magical spell on the rain drops to spare us from the pain?

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Terminal Velocity.

When you drop something in air, it does not accelerate forever. Molecules in air constantly bombard with the object, exerting an upward force. This is known as air resistance or drag.

As the object gains velocity there comes a time when the force of the air resistance is enough to balance the force of gravity, so the acceleration stops and the raindrop attains terminal velocity.

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Terminal Velocity is the maximum velocity an object can travel in air!

The Angel’s mystical spell.

Rain drops are only 0.5 mm-4 mm in diameter. Their terminal velocity is only about 10 m/s ( 20 mph ) That’s the maximum speed that they can travel in air irrespective of their initial height. Also the mass of the rain drop is about a few milligrams.

Hence, the force that it exerts on the body is really small, small enough that we find the experience pleasurable and soothing.

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