Yuri Kovalenok is a physics teacher from Russia whose physics and engineering notes are truly works of art. You can check out all of his work on his Instagram account, for your convenience, we've compiled our 10 favorite notebook pages below.

## 1. Circular motion

Kovalenok calls this one "Centripetal acceleration and force" and describes it in terms of an airplane making a turn. "The aircraft makes a turn, moving in an arc of a circle with a constant speed v=360 km/h (223.69 mph). Determine the radius R of the circle, if the body of the aircraft is rotated around the direction of flight at an angle of 10 degrees," he writes in his Instagram post description.

## 2. Tsiolkovsky rocket equation

Tsiolkovsky's rocket equation, or ideal rocket equation, describes the motion of vehicles that follow the basic principle of a rocket. It is illustrated by Kovalenok with an actual rocket, along with the equations.

## 3. Law of conservation of energy

What a perfect way to illustrate such an abstract concept as the law of conservation of energy. Kovalenok even gives a description for his drawing: "In the experiment with the "dead loop" the ball of mass *m* is released from height *h=3R* (where R is the radius of the loop). With what force presses the ball in the lower and upper points of the loop?"

## 4. Electromagnetism

What exactly is electromagnetism? Well, this illustration explains it pretty well. "Length of the movable conductor *AB* is equal to *l*. Its resistance is *R*. the resistance of the stationary conductor through which slides the conductor *AB*, is negligible. Perpendicular to the plane of the conductors applied magnetic field *B*. What force *F* must be applied to the conductor *AB*, so that it moves at a constant speed *v*. The system of conductors is in the horizontal plane."

## 5. Artificial satellite rotation

Have you ever wondered about the motion of artificial satellites? Well, Kovalenok is here to not just explain it but also to illustrate it. He also offers a little pop quiz. "The period of rotation of the satellite around the Earth is 24 hours. Find at what altitude is the orbit of the satellite?" he asks in this post's description. Can you find the altitude?

## 6. Circular motion 2

There is a second circular motion post, but this time with a car. "At the turn of the road radius of *R=100 meters* (328.08 ft) uniformly moving car. The center of gravity of the car is at a height of *h= 1 m* (3.28 ft), the width of the wheels of the track of the car *a=1.5 m* (4.92 ft). Determine the speed *v* at which the car can tip over. The car does not slide in the transverse direction."

## 7. Statics

This one stars a person doing some pretty scary acrobatics, but this is not about a circus. It is about statics. "Ladder length *l=4 m* (13.12 ft) is put to a smooth wall at an angle of 60 degrees to the floor. Maximum friction force *Ffric=200 N*. at what height h can a person weighing *m=60 kg* (132.27 lb) climb a ladder before the ladder starts to slide? The weight of the ladder can be neglected."

## 8. The Vavilov-Cherenkov Radiation

When you run a nuclear reactor that uses water as a moderator, you'll see a blueish glow. That glow is known as Cherenkov radiation — basically like a sonic boom but for light. It occurs when charged particles (such as electrons) move through a dielectric (insulating) medium — such as water — faster than the speed of light. This disrupts the electromagnetic field of the water. The particle is traveling faster than the disturbance can ripple out, forming an electromagnetic shockwave.

## 9. Self-Induction

The phenomenon of self-induction is a special case of the law of electromagnetic induction (Faraday's law). As Kovalenok explains, "despite the fact that the voltage in the tram line is about *600 V*, when opening we can get a voltage many times higher than the voltage at the source." This creates a spark where the wire meets the tram.

## 10. Thermonuclear Fusion

Thermonuclear fusion is a way to achieve nuclear fusion using extremely high temperatures. There are two types of thermonuclear fusion: controlled and uncontrolled. Here, Kovalenok's notes show the controlled version, where fusion reactions can be harnessed for constructive purposes, versus being weaponized in a device like a hydrogen bomb.

To create a controlled thermonuclear reaction, two conditions must be met, writes Kovalenok.

"First, the rate of impact of the nuclei corresponds to the plasma temperature:*T > 10E8 K* (for the D-T reaction).

Lawson criterion compliance:*NT > 10E14 cm−3· C* (for D-T reaction),

where *n* is the density of high-temperature plasma, *τ* is the plasma retention time in the system. D-deuterium. T-tritium."