Четыре краски vs Physics Zen

Можно ли карту России раскрасить в четыре цвета так, чтобы никакие два соседних региона не были покрашены в один цвет? Оказывается, так можно раскрасить любую карту — это утверждение стало первым компьютерным доказательством в науке. Вы можете проверить это на карте России, подучить немного географию нашей страны, а также побывать в стране Мартина Гарднера.

Physics Zen turns physics into focused, repeatable practice. Work through fresh generated problems, check your answer instantly, and open the theory or worked solution exactly when you need it. A COMPLETE PHYSICS PATH Practice 66 skills across 21 topics: • Mechanics: motion, projectiles, forces and friction, energy, momentum, centre of mass, rotation, circular motion, gravitation, oscillations and fluids • Electricity and Magnetism: electric fields, circuits, capacitors, RC transients, magnetic fields, induction, inductance and AC • Waves and Optics: wave graphs, sound, interference, reflection, refraction, lenses and diffraction • Thermodynamics: heat, gas laws, kinetic theory, entropy, engines and renewable energy • Modern Physics: photons, matter waves, X-rays, nuclear physics, particle physics and special relativity EXAM PREP Twelve exam paths, each built from the topics its exam actually tests: • AP Physics 1, AP Physics 2 and AP Physics C: Mechanics, with free-response items that give follow-through marks • A-Level Physics, with required-practical data analysis: tables, gradients and uncertainties • HKDSE Physics (Hong Kong) • Abitur Physik, with fine-beam tube and Wien filter labs • French Bac physics, including Newton's law of cooling and the telescope; chemistry and the practical assessment are not included • Japan's University Entrance Common Test in Physics and Basic Physics, with digit-cell answers • Korea's CSAT (Suneung) Physics I, and the physics part of CSAT Integrated Science from 2028 • Taiwan's Advanced Subjects Test (分科測驗) Physics, which also covers the physics in the GSAT (學測) science paper • Board-specific gravity conventions Every item is original practice, not an official exam paper. BUILT FOR PRACTICE Generated Problems: Practise fresh parameter combinations across multiple difficulty levels. Mastery Progression: A five-level bucket system moves from foundations to multi-step problems as you demonstrate understanding. Theory Beside the Problem: Open concise explanations, formulas and worked examples without leaving your session. Mistake Journal: Wrong answers are saved automatically. Retry the same concept later with fresh numbers. Visual Physics: Graphs, force diagrams, circuits, waves, rays, energy levels and fluid scenes support the problems that need them. Offline First: The curriculum and generator work without an internet connection. Optional sign-in adds cross-device sync. Focused Interface: No ads, no coins and no lives. Includes light and dark themes. Content is available in twelve languages: English, German, French, Spanish, Brazilian Portuguese, Dutch, Swedish, Japanese, Simplified Chinese, Traditional Chinese, Korean and Russian. HOW IT WORKS 1. Choose a section, topic or exam path. 2. Solve a generated problem at your current level. 3. Check your answer and read the worked solution. 4. Build mastery and return to mistakes that need another pass. Most skills are free, and Kinematics is free end to end. Premium unlocks the last skill of each topic, the exam-prep paths and detailed statistics. Subscription and lifetime options are shown in the app with local pricing before purchase. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel them in your App Store account settings. Privacy Policy: https://physics-zen.com/privacy Terms of Service: https://physics-zen.com/terms Support: contacts@trifoiltrailblazer.com