Dominoes

1. Content

The exhibition items consist of a domino experiment setup and videos. The domino experiment device consists of a starting push rod, two sets of domino demonstration models, a reset electromechanical device, and a glass scene box. One set of domino models is arranged in ascending order, while the other set is arranged in descending order. The last card arranged from small to large is about 1.2 times that of the previous card, and the number of models is 15 to ensure significant experimental results. Two sets of domino demonstration models are displayed in a closed glass box, and visitors cannot touch the domino models. After pushing the start push rod, the small drumstick connected to the push rod will knock down the dominoes, pushing the first domino to fall, and at the same time, the screen will display a cheering animation for the game. After the last domino falls, the principle explanation video will automatically start playing. The video adopts an animated style and introduces the physics principles of dominoes to children through steps such as reproducing the experimental process, local slow close-up videos (editing materials), and principle demonstrations. After the video is played, the dominoes will automatically reset, and the mechanical device will be in a locked state before resetting.

Domino is a rectangular domino made of wood, bone, or plastic. When playing, arrange the dominoes in rows at a certain distance, gently knock down the first domino, and the rest of the dominoes will have a chain reaction, falling one after another. The standard established by international organizations is a domino length to width to thickness ratio of 6:3:1; For example, 5.4x2.7x0.9cm, 6x3x1cm, 12x6x2cm are all standard sizes that meet this ratio.

2. Principle

There are two arrangements, where the same domino falls and hits another card with different moments and times. If it hits the top of a small domino, the force arm is large, the torque is correspondingly large, and the angular velocity is high (all from 90 ° to 180 °), so the overall falling speed is fast and the time is shorter; And for cards arranged from small to large, the smaller card falls first and hits the middle of the next card, with less torque and speed, requiring longer time.

Domino effect: In an interconnected system, a small initial energy can generate a series of chain reactions, which is known as the "domino effect" or "domino effect". The physical principle of this effect is that when a domino is upright, its center of gravity is higher, and when it falls, its center of gravity decreases. After the falling process, its gravitational potential energy is converted into kinetic energy, and when it falls in the middle of the second card, the kinetic energy is transferred to the second card. The second card then transfers the sum of the kinetic energy transferred from the first card and the kinetic energy converted from its own gravitational potential energy during the falling process to the third card. Therefore, when each card falls, it has a greater kinetic energy than the previous card, so the speed is faster one by one. That is to say, the energy that is pushed down one by one is greater. If someone really made such a set of dominoes, the skyscraper would be knocked down with a single finger!

3. Purpose

Through intuitive testing experiments, visitors can understand the physics principles and characteristics of dominoes.