EuPhO 2026, experiment — Задача 3. Task E3: Density of solid beads (3.0 pts)

Experimental task Language: English · 3 т.

Условие

Levitated objects will be situated slightly below node due to gravity. The restoring acoustic force $\vec{F}$ acting on the levitated object is proportional to $P^2$, where $P \propto U$ is the acoustic pressure amplitude at the antinodes and $U$ is the voltage from the power source.

Experimentally determine the density of the unknown beads (O) as precisely as possible. The density of the glass beads (P) is $\rho_{\mathrm{glass}} = 2500\ \mathrm{kg/m^3}$. These spherical beads (O, P) have the same size. (3.0 pts)

Hint: Depending on your approach, for spherical objects and small displacements $\Delta \vec{z}$ from the node, you may use the approximation: $\vec{F} = -f(R)\, P^2 \Delta \vec{z} \qquad (1)$ Here, $f(R)$ is some unknown function of the radius $R$ of the levitated object.

Отговори

Решение

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Оригинал в Архива: eupho2026_experiment_problems.pdf · официални решения: eupho2026_experiment_solutions.pdf