Tube Newton

A tube of Newton is a simple tube in which one makes the Vide, in order to be able to make experiments without undergoing the Frottement of the air.

It is in general about a cylindrical right to generally circular base of a given surface and a height generally equalizes to approximately 2 m, vertically posed on its basis.

The vacuum is in fact a more or less dense atmosphere: the current vacuum pumps make it possible to obtain a sufficiently thorough vacuum to show celebrates it Loi of Galileo (1602):

"All the bodies, the feather like lead, have even law of chute."

A device allows simultaneous lâchers of objects: plucks, small rigid helium balloons, lead, uranium 238, carob seed, 2 carob seeds, breaks into leaf, petal, flower of dandelion, small pot of glass, without lead or with.

Some like to say that the experiment of the tube of Newton, religieusement carried out well, wakes up a scientific vocation .

A child, spontaneously , associates vacuum and not-gravity, because if there is no more air up there it is well because G is not there any more to retain it: it is escaped “in space”. The experiment thus has teaching virtues which go well beyond the $z = 1/2 \ cdot G \ cdot t^2$ . It is necessary to insist on this even law of fall. Including an atom fall the same; including the light fall, though in a relativistic way. Very logically, if the meeting is well led, a curious and attentive child should put the question: But then, why all our air did not already fall on the ground? The professor then exploited this famous experiment well.

In 1915, Einstein posed like Principe of equivalence inert mass and Masse engraves the law of Galileo of 1602, and while reasoning as with its practice on the ultimate consequences of this postulate, he invented the equations of Einstein of the General relativity, which is especially, actually, a theory of the gravitation in geometry riemannienne.

When one releases different bodies in the air, they arrive on the ground in a nonuniform way and their trajectories are different: the fall of these bodies is nonfree. This difference of trajectory and speed is due to the effect of the air on these bodies.

A body is in freefall if it is only subjected to the effect of its weight (the conditions of freefall are defined by a fall on a small distance from an object profiled enough not to have a too large catch with the air, or in space). The movement of a body in freefall without initial speed rectilinear uniformly is varied, defined by the relations:

Z = 1/2. v · T ² where v = G · T

See too

Freefall

Random links: