21
Yakov Perelman's hilarious scientific puzzles for Google-level intellectuals
IT giants Google and Microsoft are known for imposing special requirements on job seekers. For example, candidates are tested not only with questions on their profile specialty, but also with all kinds of logical tasks. What is the connection between Jacob Perelman’s “Entertaining Physics” published in 1913? The answer is in our article.
Interesting physicist Yakov Isidorovich Perelman was born on November 22, 1882 in the city of Bialystok. His name is not associated with high-profile scientific discoveries. But Perelman’s contribution to Soviet and world science cannot be overestimated.
It is hard to believe, but his “Entertaining Physics”, which we read as a child, was first published more than a century ago, in 1913. Since then, it has generated interest in scientific knowledge among millions of children from different countries. And today is rightfully considered the ancestor of the scientific and entertaining genre.
Unlike popular science books, Perelman’s books are not just about science. They ask questions, offer tasks from real life, provide material for reflection and experimentation. On each page, the reader can make a real discovery, which encourages him to think freely and creatively.
And this is exactly what IT corporations need most today. The job market is full of high-scoring graduates. At the same time, finding employees who can demonstrate a breadth of thought and a non-standard approach to solving complex problems is not easy. Sometimes even more difficult than a grain of gold in empty rock.
That is why thousands of candidates have to pass through a sieve of intricate questions. We have already introduced some of them to our readers. We plan to introduce others soon.
Unfortunately, no one knows all the questions asked in Google interviews. In addition, they are regularly updated. But there's a way. You need to learn to find answers to non-standard questions. And help in this favorite readers and time-tested books by Yakov Perelman.
Yakov Perelman’s Funny Scientific Mysteries: When Do We Go Around the Sun Faster – Day or Night? We have one planet, and when it is night on one side, it is day on the other. Therefore, the question seems ridiculous and meaningless, but only at first glance. Well, let's figure it out.
As you read this article, our planet rotates around its axis at an enormous rate. For example, a point on the equator shifts by 500 meters every second. At the same time, the Earth orbits around the Sun. Here the speed is even higher: about 30 kilometers per second.
As you can see, we make two movements: around the Sun and around the Earth's axis. They add up. But the result is different depending on which side of the planet we are on.
Looking at the picture, you can understand that on the night side, the speed of rotation around the axis is formed with the translational speed of the Earth’s movement, and on the day side, on the contrary, it is taken away from it.
So it turns out that at midnight a resident of St. Petersburg every second moves in the solar system for half a kilometer more than at noon.
Are all parts of the wheel moving at the same speed? You may have noticed that the upper spokes of a bicycle or motorcycle wheel merge when moving fast, and the lower ones are visible separately. What is the answer to this strange phenomenon?
Once again it is hard to believe, but the top of the rolling wheel really moves faster than the bottom! As in the case of the rotation of the Earth, we observe here the addition of two motions: rotational and translational.
At the top, rotational motion is added to translational motion, and at the bottom it is taken away from it. Therefore, it turns out that with respect to a stationary observer, different parts of the wheel move at different speeds.
In what position is it impossible to get up from the chair? Few people believe that there is a position in which it is simply impossible to get up from a chair without changing the position of the legs and trunk. Sit like the boy in the drawing. No matter how you strain your muscles, you can't get up. Why is this happening?
The answer will be given by statics, a branch of physics that deals with the equilibrium of bodies. A body having an area of support is in equilibrium when a vertical straight line passing through the center of gravity of the body does not extend beyond the area of support of this body.
A standing person will not fall as long as the sheer line extending from his center of gravity is inside the platform bounded by the edges of his feet. This is why it is so hard to stand on a rope or on one leg.
In a sitting boy, the center of gravity is near the spine 15-20 cm above the navel. If you draw a vertical line from it, it will touch the floor under the chair. It turns out that to get up, you either need to tilt the body forward, or move your legs back under the chair.
In short, physics is not the formulas in a dusty textbook, but the life that surrounds us. And Jacob Perelman's books help to understand it better!
Interesting physicist Yakov Isidorovich Perelman was born on November 22, 1882 in the city of Bialystok. His name is not associated with high-profile scientific discoveries. But Perelman’s contribution to Soviet and world science cannot be overestimated.
It is hard to believe, but his “Entertaining Physics”, which we read as a child, was first published more than a century ago, in 1913. Since then, it has generated interest in scientific knowledge among millions of children from different countries. And today is rightfully considered the ancestor of the scientific and entertaining genre.
Unlike popular science books, Perelman’s books are not just about science. They ask questions, offer tasks from real life, provide material for reflection and experimentation. On each page, the reader can make a real discovery, which encourages him to think freely and creatively.
And this is exactly what IT corporations need most today. The job market is full of high-scoring graduates. At the same time, finding employees who can demonstrate a breadth of thought and a non-standard approach to solving complex problems is not easy. Sometimes even more difficult than a grain of gold in empty rock.
That is why thousands of candidates have to pass through a sieve of intricate questions. We have already introduced some of them to our readers. We plan to introduce others soon.
Unfortunately, no one knows all the questions asked in Google interviews. In addition, they are regularly updated. But there's a way. You need to learn to find answers to non-standard questions. And help in this favorite readers and time-tested books by Yakov Perelman.
Yakov Perelman’s Funny Scientific Mysteries: When Do We Go Around the Sun Faster – Day or Night? We have one planet, and when it is night on one side, it is day on the other. Therefore, the question seems ridiculous and meaningless, but only at first glance. Well, let's figure it out.
As you read this article, our planet rotates around its axis at an enormous rate. For example, a point on the equator shifts by 500 meters every second. At the same time, the Earth orbits around the Sun. Here the speed is even higher: about 30 kilometers per second.
As you can see, we make two movements: around the Sun and around the Earth's axis. They add up. But the result is different depending on which side of the planet we are on.
Looking at the picture, you can understand that on the night side, the speed of rotation around the axis is formed with the translational speed of the Earth’s movement, and on the day side, on the contrary, it is taken away from it.
So it turns out that at midnight a resident of St. Petersburg every second moves in the solar system for half a kilometer more than at noon.
Are all parts of the wheel moving at the same speed? You may have noticed that the upper spokes of a bicycle or motorcycle wheel merge when moving fast, and the lower ones are visible separately. What is the answer to this strange phenomenon?
Once again it is hard to believe, but the top of the rolling wheel really moves faster than the bottom! As in the case of the rotation of the Earth, we observe here the addition of two motions: rotational and translational.
At the top, rotational motion is added to translational motion, and at the bottom it is taken away from it. Therefore, it turns out that with respect to a stationary observer, different parts of the wheel move at different speeds.
In what position is it impossible to get up from the chair? Few people believe that there is a position in which it is simply impossible to get up from a chair without changing the position of the legs and trunk. Sit like the boy in the drawing. No matter how you strain your muscles, you can't get up. Why is this happening?
The answer will be given by statics, a branch of physics that deals with the equilibrium of bodies. A body having an area of support is in equilibrium when a vertical straight line passing through the center of gravity of the body does not extend beyond the area of support of this body.
A standing person will not fall as long as the sheer line extending from his center of gravity is inside the platform bounded by the edges of his feet. This is why it is so hard to stand on a rope or on one leg.
In a sitting boy, the center of gravity is near the spine 15-20 cm above the navel. If you draw a vertical line from it, it will touch the floor under the chair. It turns out that to get up, you either need to tilt the body forward, or move your legs back under the chair.
In short, physics is not the formulas in a dusty textbook, but the life that surrounds us. And Jacob Perelman's books help to understand it better!
