Russian problems often have a hidden conserved quantity (energy, momentum, angular momentum) or constraint (inextensible string, no-slip condition). Find it first.
Instead, he found a page that wasn't scanned. russian physics olympiad problems pdf
A uniform rod of mass m and length L is hinged at its upper end. The rod is initially held horizontally and then released. At the lowest point of its swing, the rod strikes a stationary block of mass M resting on a frictionless surface. The collision is perfectly elastic. Russian problems often have a hidden conserved quantity