Le matérial dont nous avons besoin pour réaliser l'expérience est:
Un verre Unemonnaie Une carte d'un jeu de cartes
Préparation
Mets la carte sur le verre et la monnaie au centre de la carte. Fixe le verre avec une main et tire la carte avec l'autre main avec énergie. Le monnaie tombe dans le verre.
Qu'est-ce qui s´est passé?
La résistance d´un corps à changer son état de repos ou de mouvement s´appelle inertie. Après avoir tiré la carte, la force de frottement entre la carte et la monnaie tend à deplacer la monnaie sur la carte. Si nous le faisons avec énergie, la force de frottement ne réussit pas à surpasser l´inertie de la monnaie qui tombe dans le verre. Mais si nous tirons lentement de la carte, la monnaie se déplace sur la carte.
Un pot de verre avec un couvercle Une paille de rafraîchissement Colle Alcool
Nous pouvous faire un trou sur le couvercle avec un marteau et un clou.
Nous mettons la paille dans le trou et nous remplissons d´alcool le pot (plus ou moins deux centimètres). Et nous plaçons le couvercle.
Nous couvrons le pot avec nos mains et nous voyons que l´alcool monte par la paille.
Explication
La température de notre corps est supérieure à la température de l´air dans le pot Pour entourer le pot avec nos mains fournissons de l´énergie au pot et comme ça augmente la température de l´air dans le pot. Cela produit l´augmentation de la pression aussi qui pousse le liquide que monte par la paille.
Si nous levons le convercle du pot, la pression dans l´interieur récupére sa valeur originale et le liquide qui monte par la paille tombe dans le pot.
This is an experiment about plasma. In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule. The ability of the positive and negative charges to move somewhat independently makes the plasma electrically conductive so that it responds strongly to electromagnetic fields. Plasma therefore has properties quite unlike those of solids, liquids or gases and is considered to be a distinct state of matter.
A movie that gives a good idea of atmospheric pressure. Our atmosphere is capable of keeping a papel up even against a glass full of water. In fact, one would need a column of water with a height of about 10 meters in order to have equal water and air pressures.
To make our experiment we need a bottle of plastic of 1´5 litres, a sheet of paper and a few matches.
First we make a couple of holes in the bottle of plastic, one in the top part and another one near the base of the bottle.
Them we take the sheet paper and cut away a rectangle of 10x15 cm (10 times fifteen). We coil the paper to obtain a small cylinder of approximately 15 cm of length. Finally the small tube of paper interferes for the top hole of the bottle.
On having ignited the small tube of paper with a match a small flame is formed and is observed that for another end of the bead goes out a column of very dense smoke that falls down inside the bottle. In the exterior scarcely there is smoke.
If we cover the low hole with a finger, the small tube of paper goes out and smoke doesn’t go out.
Explanation:
On having burned the small tube it departs from the paper it is clear in the shape of particles that, together with the gases that formed in the combustion and the air they form the smoke.
In normal circumstances, the smoke ascends dragged by the warm air of the combustion.
In our experiment, the smoke that takes place is produced in the interior part of the small tube travels along it. Inside the bottle, there is no warm air, so that, when the smoke goes out for the low end of the small tube there aren’t produced rising currents of convection and the smoke, denser that the air, it rushes to the bottom of the bottle.
1 Stand the spaghetti placed about your two hands. 2 It moves slowly one of the hands towards the other one without inclining the spaghetti. 3 Regardless of the hand that moves the two end up together in the center of the spaghetti that will remain in balance without falling.
Explanation:
By moving the hands, spaghetti slides without falling, keeping the gravity center between the fingers.
In order to make our experiment, we only need a bottle of water with it’s cap.
We make a small hole in a plastic bottle, about a half of its height, and we fill it full of water, while we are covering the hole.
If we remove our finger from the hole, no water comes out, but if we remove the cap of the bottle, the water starts to come out. But why?
If the cap is put, the internal pressure on the hole is equal to the external pressure and that’s why the water doesn’t come out of the hole.
But, if we remove the cap, we allow that the air comes into the top of the bottles, breaking the previous balance. The internal pressure on the hole is greater than the external pressure, so the water comes out of the bottle.
To make our experiment we need a pair of forks, a toothpick, a glass and a match.
First, we have to intertwine the forks with the toothpick and leave them in balance at the edge of the glass. The balance is obtained because the centre of the gravity is under the support point.
What would happen if we burnt the edge of the toothpick that is inside the glass?
A part of the toothpick is burnt, but the flame is put out when it’s at the edge of the glass and the balance of the forks is kept.
The loss of volume of the toothpick that is burnt, doesn’t affect to the centre of the gravity
To make our experiment we need two plastic bottles of one and a half litres.
First, drill a hole in the two bottles corks. Then, fill one of the bottles with water to about three quarters and join the two plugs per cylinder. To unite the two bottles it can be used a tape.
It is very important the union between the bottles.
When the water on the bottles is empty is upper, it seems that the water does not fall easily to the bottle bottom, but if we give a circular motion to the bottle top and creates a swirling, water falls easily.
By placing the bottles on top, water doesn’t fall to the bottom because of the compressed air trapped in the bottle which is down. It can pass through it, as there is no room for it.
When the eddy is generated by moving the top bottle, it is communicated the air in both bottles and the water in the top bottle falls easily into the bottom bottle.
To make our experiment we needs a plastic bottle, sand beach and a rope.
First we have to construct a pendulum with the bottle. Them we cut the base and make a couple of holes in one of the sides in order to pass the rope and another hole in the stopper to exit the sand filled.
If the bottle is away from the position of equilibrium it begins to oscillate, describing a trajectory that will be recorded in the soil by the stroke that left the sand that falls from the bottle.
Depending of the length of the rope and on the relationship between distances, we can get different figures.
The figures obtained are known as Lissajous figures, names after French scientist Jules Antoine Lissajous, who first observed this in 1857.
1. A small container and a big glass. 2. Oil 3. Water 4. Alcohol 5. Glue and coin. 6. A spoon.
If the container is made of plastic, we stick a coin at its base in order to get more stability and avoid floating.
We fill the half a container with oil. We put it at the bottom of the glass. We pour the alcohol necessary to cover the container very carefully.
Then, we add water little by little with a spoon (it must slip from the wall of the glass). Small container's surface filled with oil will adopt a convex shape until the water you add is enough. Then, the oil will separate from this container and it will have a spherical form that will remain just in the middle inside the oil and water mixture.
EXPLANATION: First, we must know the densities of the liquids we use in the experiment. - water (1g/ml) - oil (0'92 g/ml) - Alcohol (0'75 g/ml)
The oil floats in the water because it's less dense than water, but it sinks into alcohol because it's denser than it. In conclusion, you can prepare a mixture with alcohol and water because inside it, oil won’t float or sink.
The materials we need to do the experiments are a balloon and drawing pins.
First you have to push the balloon against twenty drawing pins and make sure they don't explode. The strength exerted has distributed on all the drawing pins so there isn’t sufficient pressure to explode the balloon.
The effect of strength doesn't depend only on its intensity, but also on the surface on which exerts. If the surface is very large, the effect of the strength will be spread over it all.
Next, push the balloon against one drawing pin and notice if it explodes. In this case, all the strength mass and pressure at a very specific point makes the drawing pins go through the balloon and explode.If on the contrary, the surface is small, the intensity of the strength mass over it is stronger and its distorted effect increases.
