For problems you can't start, look at the first two lines of the GDZ solution to find the "starting formula," then close the GDZ and try to finish the rest yourself.
степанова г.н. сборник задач по физике для 9—11 классов gdz po fizike 9-11 klass g.n.stepanova
Stepanova’s collection is structured to build physical intuition through a vast range of problems, from basic conceptual questions to complex multi-step calculations. For problems you can't start, look at the