obsidian_backup/补课/多体动力学/13_mass_distribution.ipynb

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{
"cells": [
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [],
"source": [
"import sympy as sm\n",
"import sympy.physics.mechanics as me\n",
"me.init_vprinting()"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [],
"source": [
"m1, m2, m3, m4 = sm.symbols('m1, m2, m3, m4')\n",
"N = me.ReferenceFrame('N')"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [],
"source": [
"r1 = 3*N.x + 4*N.y\n",
"r2 = 3*N.y + 4*N.z\n",
"r3 = 4*N.x + 4*N.z\n",
"r4 = 3*N.y + 4*N.z"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [],
"source": [
"first_moment = m1*r1 + m2*r2 + m3*r3 + m4*r4"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {},
"outputs": [],
"source": [
"zeroth_moment = m1 + m2 + m3 + m4"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "MinerU",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.10.16"
}
},
"nbformat": 4,
"nbformat_minor": 2
}