1, Hercules "paper" hand (paper to water):
Steps: first of all, the cup will be full of water does not overflow; and then cover the paper in the cup, the paper and the cup with the upside down; at this time, the water will not flow out, and will not soak the paper.
Principle: the cup will be filled with water, the paper cover, there is no air in the cup, upside down, the outside atmosphere will produce buoyancy on the cup and the water, resulting in water does not flow out.
2, the air in the trick (balloon blowing):
Steps: prepare a balloon and an empty bottle, the balloon into the bottle; pull the balloon blowing mouth, reverse buckle in the bottle mouth; mouth to the bottle mouth blowing hard, you despite the maximum effort, blowing red, see what results; balloon is just a little bit bigger, but how to drum up.
Principle: There was air in the bottle, and when the balloon's mouth was backed up against the bottle's mouth, the air was sealed in the bottle. When blowing, the volume of the air inside the bottle is compressed and reduced, so the pressure inside the bottle increases, and the pressure on the balloon increases, and when the pressure inside the bottle is equal to the pressure generated by blowing the balloon, the balloon can no longer be blown up.
3, the book of the tug-of-war (two books can not be separated):
Steps: put the notebook on the table, they are bound on one side relative to each other, and in the middle of the width of a notebook (in order not to destroy the book, you can use the two notebooks to do the experiment); overlap the notebook in turn on each page; until all of the paper overlap together, at this time we gently pressure together; hands to the the notebooks up and try to separate them.
Principle: it is with the help of friction. Objects in contact and have a tendency to move relative to each other will produce friction. When the pulling force is greater than the friction or the contact surface is smoother, the two objects can be separated. Two sheets of paper folded together also have friction, but not enough to make us notice, and as the number of sheets increases, the friction between the paper is also greater, and exceeds our pull, so how we can not separate the two notebooks.
Expanded information:
Beijing Science and Technology Museum Exhibits
The new museum's public ****space is also home to a number of distinct exhibits, spread across the ground floor of the new museum's exhibition halls From the first to the fourth floor, unique exhibits include:
Small Ball Array - located in the ceiling of the west hall on the first floor, 805 small balls with a diameter of 26 centimeters suspended by steel wires form an array 18 meters long and 12 meters wide; under computer control, motors manipulate the small balls up and down in the air in a straight line to form different geometric patterns.
Life Spiral - located in the south hall of the first floor, a huge double helix sculpture shape (47 meters high) composed of human bodies, showing that DNA is the basis of all life on earth and the beauty of its shape.
Mechanical Melody--Located in the first floor science gallery, the combination of various gears, connecting rods, cylinders, pistons, cams, apertures, sliders, wheels and oscillating structures, etc., expresses the beauty of the machinery and its metal materials themselves by means of the complex mechanical devices, their linkage relationship and operation process.
Molecular Motion Wall - located in the south hall of the first floor, more than 20 hemispherical "molecular sliders" move freely and collide with each other, which is similar to the Brownian motion of the microscopic particles in the expression of the movement of the beauty of the reproduction of molecules and molecules of the free movement and the process of mutual collision. and the process of mutual collision.
Dynamic deformation wall - located in the north corridor on the second floor. Hundreds of cylinder rods are driven by computer-controlled solenoid valves to expand and contract the movement, so that the wall surface produces regular ups and downs of deformation, composed of specific patterns or characters, etc., and can produce the effect of launching the audience with their backs to the wall surface.
Life course - located in the underpass. The 68-meter-long art glass relief mural shows the birth of life on earth, the evolution of the course of life in turn from west to east, containing the idea of the evolution of life and the evolution of life and the relationship between the environment.
The Wheel of Time is located on the third floor of the North Rotunda. The transparent dial reveals its internal complex and delicate mechanical structure and parts, and through the modeling of the clock structure and mechanical movement, it expresses the complex and delicate mechanical structure and operation process inside the clock.