Start Physics

Study school physics in one flow: concepts, worked examples, practice, review. No account. No internet connection needed. The app follows your device language —— English or Korean. Switch at any time; your records carry over. ■ It traces the gap If you keep missing conservation of mechanical energy and the real gap is in work and kinetic energy, solving the same problem a hundred more times will not help. This app gathers the concepts behind your wrong answers, walks back along the prerequisites to the weakest one, and tells you where to start again. A unit you reach this way opens its concepts and examples even when it is locked, and it stays open. Sometimes the gap is in math. When it is, the card says so plainly, so you know to go back to your math course rather than read the physics again. ■ Constants are given inside the problem Some textbooks take gravitational acceleration as 9.8 m/s², others as 10. If the answer depends on which book you own, that is guessing, not study. Every problem states the constants it needs: "Take g = 10 m/s²." ■ A grader that knows units If the answer is 40 N, 0.04 kN is right too. Unit prefixes, conversions such as km/h to m/s, and tolerance for decimal answers are all handled, and every grading rule is covered by automated tests so that a right answer is never marked wrong. Questions never say "answer in newtons". The answer box shows the unit. Written answers accept the forms people actually write —— "valence band" or "the valence band", "3" or "3 times". ■ Wrong answers come back when you are about to forget Missed problems go into a review notebook and return after 1, 3, 7, 16 and 35 days. Get one right and the interval grows; miss it again and it starts over. You can mark why you missed it —— a slip in the math, an idea you misunderstood, or a question you misread. A slip does not lower your mastery of the concept, and it comes back in three days instead of one. ■ Formulas and diagrams are typeset, not pasted No formula is an image. Fractions, radicals and vector arrows are drawn by typesetting rules, so nothing blurs when you make the text larger. Free-body diagrams, circuits, magnetic fields, energy levels and ray diagrams for lenses —— 92 figures drawn from coordinates. With VoiceOver, formulas are read aloud the way a teacher says them: "1 over 2", "v squared", "the square root of 2 g h" —— and units by name, "meters per second squared", not "m divided by s squared". ■ Concepts you can move Six simulations —— resultant force, gravity and weight, elastic force, friction, buoyancy, and how a net force changes motion. Drag the values and watch what happens; it is quicker than reading about it. ■ What is inside · Middle School Physics (Grades 7–9) —— forces and their effects, heat, light and waves, electricity and magnetism, motion and energy (250 problems) · Integrated Science: Physics (Grade 10) —— foundations of science, mechanical systems, electrical properties of matter, energy conversion and power generation (190 problems) · Physics (Grade 11) —— force and equilibrium, momentum and mechanical energy, heat and energy conversion, electric fields and circuits, magnetic fields and electromagnetic induction, the wave nature of light and lenses, quanta and matter (350 problems) 79 lessons, 790 problems, 99 concepts and a 133-entry glossary, all in English. Every problem was written for this app. The courses follow South Korea's 2022 national curriculum, including the limits its commentary sets —— where it says a topic is to be treated qualitatively, we do not ask for numbers. ■ Buying One purchase per course. Not a subscription, never expires, Family Sharing on. Without buying, the first two lessons of every chapter stay open —— 320 problems, 40% of the app. ■ Requirements iOS 18.0 or later. No account. Works offline. Your study records stay on your device and in your own iCloud.