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# Monthly Archives: August 2011

## Science model on energy transformations

I have got an assignment from school about making an energy transformation model and I have no idea what to do!
Can you help me? (Posted by Maddy on 28 Aug 2011)

(Expecting suggestions from visitors and members)

There are many simple models for energy transformation. One of the themes for this years Science Exhibitions suggested by NCERT is “Energy Conservation”.

Any generator is a device for energy transformation.

You can think of any device which can convert energy from one form to another.

## A Numerical Problem on conservation of momentum – An exploding shell

An 80 kg shell is flying at a speed of 36km/h. It explodes into two pieces and one piece of mass 20 kg stops. What is the velocity of other piece?

(It’s a simple problem. Expect the visitors to answer soon)

## Dimensions and conversion of units

The height of mercury column in a barometer in a Calcutta laboratory was recorded to be 75 cm. Calculate this pressure in SI and CGS units using the following data : specific gravity is 13.6, density of water is 1000 kg/m3, g is 9.8 m/s2 at Calcutta. Pressure = hρg in usual symbols

## Ideas on the Origin of Universe

Well, nobody knows it exactly. Physics and other sciences can explain How things go or went, not Why. Althought there is a theory, called the M theory or the 11 dimensions theory, that gives a kind of answer to this: the M theory says that the matter is made of little strings that vibrating give to the matter his properties. To ensure all the properties 10 dimensions are necessary: the classical 4 (3 for the space + time) and 6 circumvented dimensions. Well the 10 dimensions theory was not able to explain some phenomenons, as the divergences between relativity and quantum mechanics. in 1995 a phycisist found that assuming the existence of an 11th giant dimension, all was explained. think about this dimension as a giant room where there are sheets hanging from the ceiling. well these sheets are parallel realities. Our universe is in one of these “sheets”. In this frame we have the creation of a universe (a big bang) every time a sheet touches another sheet.

I’ve just described you the frontier of the theoretical physics.

– Daniele G. M / Ancona, Italy

Visitors can respond to the idea given by Daniele

## Tossing a coin in a moving train.

if a man tossed a coin in a moving train and the coin fell back then in which type if motion train is moving? and how?

Answer: This shows that the train is accelerated. When the coin was thrown, it had the same velocity of the train. If the train was not accelerated, the coin would have fallen on to the hands of the man itself. But the accelerated train moves a greater horizontal distance than by the coin.

## The SI & CGS unit of time is same .Why?

Almost in all systems of unit second is the unit of time, most probably because, second is the most convenient one, if we look at the guidelines for selecting a unit.

For more details refer to the following links

## Displacement and acceleration in real life

HOW DISPLACEMENT,ACCELERATION ACTS IN REAL LIFE PLZ GIVE SOME EXAMPLE.

(The question was posted by Chandrima )

As you know, the displacement is the shortest distance between two points ; the initial point and the final point. The displacement is independent of the path followed by the object and this itself is the beauty of the concept of displacement. We may take different paths to reach a destination, and the length of the path may be different, but all the paths result in the same displacement.