发布时间:2025-01-24 21:03:02
质量=体积×密度
圆片体积
=2兀r²×0.7×10^-3m³
=2兀0.13²×0.7×10^-3
铁的密度7850kg/m³
所以,
质量=2兀0.13²×0.7×10^-3m³×7850kg/m³
=2×3.14×0.13²×0.7×10^-3×7850kg
≈0.583kg
单栓组合式消防箱配两个灭火器,19㎜水枪一个,25米水带一个,水泵按
2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02 2025-01-24 21:03:02