EuPhO 2026 — Задача 1. Jumper (10 pts)

Автор: Olympiads XYZ · транскрипция на официалните материали

Проверена срещу оригинала на 13.9.2026 от същия модел, който я е транскрибирал (без независима проверка)

Съдържание

УсловиеРешение

Theoretical Problems · 10 т.

Условие

Two uniform rods, each of mass mm and length \ell, are connected at one end by a hinge equipped with a torsional spring. The spring exerts equal and opposite restoring torques τ\tau on the rods about the hinge,

τ=2kθ,\tau = 2k\theta,

where 2θ2\theta is the angle between the rods (in radians), and kk (kmgk \gg mg\ell) is the torsional spring constant.

The system is placed on a flat horizontal surface with the free ends of the rods resting on the floor and the hinge above them. The hinge is then pushed downward until the rods lie flat on the floor in opposite directions, corresponding to θ=π/2\theta = \pi/2. Friction between the rods and the floor is negligible.

Jumper jumps after the hinge is released. Determine the maximum height hh reached by the center of mass of the system to a precision better than 1%.

Drawing of two rods forming a triangle standing on a horizontal floor, joined at the top by a hinge (drawn as a ring); the apex angle is labelled $2\theta$ and the torque $\tau$ is indicated by an arc arrow near the apex.

Решение

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Оригинал в Архива: eupho2026_theory_problems.pdf · официални решения: eupho2026_theory_solutions.pdf