The fundamental laws of physics, known from school, are usually easy to remember. But
Of course, reproduce Newton's laws yourselfit is not required every day: you need to explain them to your child, you want to test your knowledge in physics, "play" something tangible, not digital models, or remember something long forgotten from school days. No laboratory facilities are required for this. And you can do with only models consisting of wood and rubber bands. The UGEARS constructors provide this opportunity. The main thing is to observe the accuracy of the assembly, whatever the basic laws of physics are, for them to work, certain conditions are also needed. We will tell you what natural science canons can be checked on wooden models and what is needed for this.
Monowheel. Mechanical balance
The electric unicycle today has become almost the samea popular form of urban transport, like a hoverboard, electric scooter or bicycle. What speed lovers drive - an electric self-balancing unicycle - is just a modern modification of the unicycle, which was widespread in the late 19th - early 20th centuries. Only then, instead of an electric motor, they used human muscle strength, as in the case of a bicycle. But for balance, instead of sensors, gyroscopes and accelerometers, only talents, dexterity and experience were needed.
The unicycle device is based on the principlemechanical balance, which is important to maintain during movement. The unicycle is able to maintain an upright position as long as the wheel is held under the center of mass (as indicated by the theory of an inverted pendulum). And the desired position, as already mentioned, is set by the rider. In fact, on a unicycle, it is the person, subconsciously sensing where his vehicle is falling, compensates for the fall by moving the wheel to the point below him, where the center of mass is. It is important to do this until the unicycle falls.
The acceleration of the unicycle determines the distance fromthe center of gravity to the point of contact, and the speed and direction of rotation of the wheel - the relative position of the contact patch, and with it the nature of the dynamics of acceleration. Therefore, in order to accelerate, the rider must shift the center of gravity forward, and if slowed down, backward. And to start moving, you actually need to "fall" - just a tilt of the body, movement of the arms or hips to give the unicycle acceleration.
UGEARS to demonstrate these mechanics principlesthere is a self-propelled unicycle. The wooden model consists of 300 parts, and it is driven by a rubber motor, which, thanks to balancing (no rider talent is required here), allows the wheel not to fall. When the energy of the rubber motor runs out, the legs attached to the wheel are removed, and it begins to rotate like a simple wheel and eventually just turns over beautifully. If you fix the legs, it will also continue to move, but like a balancing wheel.
Chronometer. The pendulum and the principle of mechanical clocks
For the first time, man began to measure time usingmechanical watches in the 8th century in China, from where the technology of the liquid escapement first came to the Arab world, and then came in a slightly different form to Western Europe. There, mechanical watches had only an hour hand, and were set in motion by winding a kettlebell mechanism. The clock became the center of human life - they were installed on the main town hall towers of cities, they celebrated not only noon or midnight, but also church holidays.
In addition to the dial familiar to everyone,A mechanical watch consists of an energy source (this can be either a weight or a spring), an escapement mechanism that turns continuous rotation into an oscillatory or reciprocating motion, and a regulator - it can be a pendulum or a balance. The trigger mechanism and the engine are usually connected by a system of gears.
Of course, mechanical watches are not as accurateas their electronic or quartz "descendants". The error can range from +40 to –20 seconds per day. And today it is mechanical watches that are mainly used to maintain traditions.
A mechanical watch is based on a system thatcalled a pendulum by physicists. This is a mechanical system that performs mechanical vibrations while suspended in a gravity field. In the process of oscillation, the kinetic energy of the pendulum turns into potential (this is the energy of the force of elasticity and gravity) and vice versa. And the forces of friction gradually convert this kinetic energy into heat, due to which the amplitude of the oscillation gradually decreases.
Check how such a mechanicalsystem, as well as create your own chronometer, you can also from wood. The rubber motor will again act as a source of energy for such a device, and in order to start the chronometer for a certain time (in this case, the timer works in the interval of up to 20 minutes), it is enough to move the dial hand by a certain amount. Of course, first you have to become a watchmaker and assemble an open gear mechanism. In this case, accuracy is more important than ever.
Tram. Torque, transformation of potential tension energy into mechanical work
Feel like Fedor Pirotsky,the inventor of the first electric tram in Russia, it is possible with the help of the model. But first, it's better to understand how the tram is actually set in motion. The ancestor of electric transport was a simple horse tram, where a carriage with passengers was dragged along the rails by horses. With the onset of the electric age, motors are driven by traction.
In modern trams, the most commonly usedDC traction motors, since this is the current consumed by the tram system. But electronics allows converting direct current into alternating current, which means that AC motors can also be used in equipping trams. Moreover, unlike DC motors, they do not have a collector-brush assembly that quickly deteriorates. It is he who constantly needs repair and maintenance.
To transfer energy from the engine to the axle of the wheelset, the cars are equipped with a cardan-reduction gearing, which consists of a mechanical gearbox and a cardan shaft, respectively.
To build your own gearbox, you neednot much effort if the calculations are already done for you. This mechanism is based on the function of reduction - reducing the effort required to drive a device that converts the transmitted power into useful work. The easiest way to do this is a pair of interconnected cylindrical gears of different diameters: the drive gear is the smaller one.
In a wooden model of a tram lineno electricity needed. In addition to the fact that the connection does not even require glue, and all materials are made of wood, the same rubber motor is used as an energy source, which must be wound up - according to the principle of tensioning a spring. The transformation of energy into rotational energy, just like in a real tram, occurs due to a gear drive. In addition, the tram can move simply due to the difference in heights, then again the conversion of potential energy into kinetic energy occurs.
Pneumatic motor. Conversion of compression energy into mechanical work
The air motor was invented a long time ago,practically fulfilling the old dream of mankind: to receive energy from the air. Another thing is that first this air must be compressed, which, of course, also requires significant energy. Of course, the use of pneumatic motors and drives greatly expands the scope of various devices when increased safety is required and the use of electricity or combustible substances is not possible.
And such a physical principle can have applicationsbe a great multitude. Almost all of them were defeated by electricity. However, history remembers both pneumatic mail and even the pneumatic railway. In 1861, the first locomotive in history with a pneumatic drive was built in St. Petersburg. It was named after its creator - Baranovsky’s spirit.
Oddly enough, the air motor can be assembled andmade of wood. Moreover, almost a complete analogue of the present, including a tachometer. To start the engine, of course, air is required. In order not to deviate from the paradigm - only wood and rubber, the creators of the designer suggest using an ordinary balloon, which can be inflated and connected to the engine using special nozzles and a bell. In this case, the air will set in motion the pistons of the pneumatic device and create kinetic energy.
Arcballista. Converting tension energy into flight energy
Throwing weapons were used by humansquite a long time ago - in the Ancient World and the Middle Ages. However, today you can find similar weapons, in particular in sports, where bows and crossbows are used. The operation of such tools is based on the transformation of human muscular efforts into the energy of flight. To make this energy higher, it is possible to accumulate potential energy using elastic elements or a counterweight. In a bow or crossbow, this is a string.
Hypertrophied version of the crossbow - arcballista- was used as a siege weapon in the capture of cities and fortresses. The bow, the length of which reached 3.5 m, was attached to a massive wooden box on a wooden carriage frame, located on two large-diameter wheels. The bowstring was pulled by the artilleryman using a gate mounted on the frame. Today, of course, such devices are found only in computer games. True, the foundations of artillery were laid just then.
Classic military vehicle in the form of a wooden modelis unlikely to be able to capture a real castle, but it will work out to play an "analog" computer game. The model consists of two parts: a firing unit and a base with adjustable supports, which stabilizes the structure during firing. And such an arcballista shoots with wooden bolts. If desired, of course, you can launch something else. It is important to remember, like any artilleryman, that for a competent strike you need to correctly set the angle vertically and horizontally, and not just activate the trigger.
The fact that wooden toys are outdated can be easilyrefute by showing one of these models. And if you also talk about the laws of physics that set them in motion, derive a couple of formulas and draw the direction of the force vectors involved in the creation of different types of energies, then the word "designer" itself will no longer refer to models, but to their owners.
If you decide to purchase one ofconstructors, use the promo code HIGHTECH, it gives a 20% discount. Now in the UGEARS catalog there are 73 models, including a really lockable safe, a sports car and a bike, a pistol, a box with a secret, a large locomotive with a tender.
Read also
The most distant and ancient galaxy in the Universe has been found
20 new species of animals and plants found in the Andes
Scientists have found out where the red giants disappeared from the center of the Milky Way