Rubber, docks and different elasticities | Science | EUROtoday

The 6 cigarettes of infinite size of final week, which might contact so that every one touches everybody else, are improvable: within the determine we see an answer with 7 cigarettes, which, as well as, just isn’t distinctive (can you discover one other?). Some contacts are evident, however others not a lot; For instance, how can we ensure that C5 cigarette performs to C6?

As for the query associated to the elastic rubber, it was a entice query: if the rubber didn’t change quantity (or what’s the identical, of density), when the diameter of its part is decreased by half, the realm of ​​it will be 4 occasions decrease and, due to this fact, the size must be 4 occasions larger, that’s, 4 meters. But if the rubber didn’t cut back its quantity when stretching it will not be elastic, it will be like gum, and wouldn’t recuperate its unique type when it releases it (and due to this fact there could be no Poisson coefficient). When stretching an elastic rubber, polymers (very lengthy molecules) that compose it, tangled in a zigzagging means, stretch, which produces a quantity discount. When launched the rubber, polymers recuperate their unique type because of the structural forces of the lengthy molecules. In a means, it’s as if the elastic rubber was fashioned by an infinity of microscopic springs (microphysicists, fairly), as many as molecules.

An elastic board

And talking of elasticity, our board could carrolliana A few weeks in the past I used to be not as loopy because it appears at first look, however merely used some considerably elastic ideas. Thus, equality 180 = 90 + 30, maybe, is solely incomplete, and lacks add + 60 to finish the connection between the angles of a rectangle triangle that’s half of an equilateral.

On the opposite hand, solely within the euclidean aircraft the angles of a triangle add 180º. A triangle whose angles add 270º we are able to simply decide it on the earth’s floor: a vertex could be the north pole (or the southern pole) and the opposite two, respectively, the cities of Quito (Ecuador) and Libreville (Gabon), each situated within the geographical Ecuador and distant from one another about 10,000 km.

As for the rectangle triangle partially hidden by the top of the younger blonde, if we dispense with the 180 inside, we are able to suppose that the hidden worth of the proper angle is 70º; Only are usually not sexagesimal levels: the unique younger women divide the circumference into 280 unit arches as an alternative of typical 360.

And, as Benedicto Torres factors out, Poisson could seem in italics as a result of the concealer has thought of it a international phrase, since in French it means “fish.”

Finally, and within the line of the connection between elastic gums and docks, a proposal of our typical commentator Francisco Montesinos:

I can consider the following cooked dish. Suppose a excessive spiral top dock enrolled forming a cylindrical bran or radio spiral R. Then we stretch it by means of considered one of its ends, maintaining the opposite fastened till its top is doubled. The query is, what would be the radius of the brand new cylindrical spiral supposed a uniform deformation?

OTHER: What is the size of the unrolled dock?