Силы в упряжке

Why do a raft and a bathyscaphe float, how do a helicopter, an airplane, a hot air balloon fly? How are the propeller and wings of an airliner arranged? This and much more is discussed in our book.
The heroes already familiar to you, Bobrenok and Cat Scientist, will help you understand the intricacies of the operation of various devices, talk about how mechanisms and machines are set in motion. Inertia and gravity, friction and pressure - all of them are "harnessed" to the engines of various means of transport and apparatus.
You will read about all this on the pages of our book. Let's find out and understand how it works!
For elementary school children.