物理题目帮助---**Problem Section 1**
**Question Stem:**
• 一个正方体铁块，底面积是0.04m², 放在水平桌面上，对桌面的压力为400N, 求这个铁块对桌面的压强是多少？
**Mathematical Formula/Calculation:**
P = F / S = 400N / 0.04m² = 10000 Pa
**Problem Section 2**
**Question Stem:**
• 甲, 乙, 丙三个实心正方体放在水平桌面上，它们对桌面的压强相等, 则对桌面压力最大的是 ______ 密度最大的是 ______ 如果三个正方体上分别放一个质量相等的铜块, 则三个正方体对桌面压强最大的是 ______ (均选填甲/乙/丙)
**Diagram Description:**
Type: Simple block representation.
Main Elements: Three rectangles labeled "甲", "乙", "丙" from left to right on a horizontal line representing a table. The rectangles represent cubes of different sizes: 甲 is the largest, 乙 is medium, and 丙 is the smallest.
**Handwritten Notes/Formulas:**
1. F=pS P=Spk .:F大 (Likely relates pressure, Force, Area, and possibly a coefficient)
2. P=pgh P=hpk .:Pp大 (Likely relates pressure, density, gravity, height)
3. * P=Po + ΔF/S ΔF=内力-外力 (Relates pressure, initial pressure, change in force/area, internal/external forces)
**Problem Section 3**
**Question Stem:**
• 甲乙两只底面积相同的轻质容器内盛有液体置于水平桌面上时, 液面相平如图所示, 若两容器底部受到液体的压强相等, 则容器中液体的密度 甲 ______ 容器中液体的密度 乙, 甲容器中液体的质量 甲 ______ 容器中液体的质量 乙, 甲容器对桌面的压强 甲 ______ 容器对桌面的压强 乙 (均选填大于/等于/小于)
**Diagram Description:**
Type: Schematic diagrams of containers with liquid.
Main Elements: Two containers, labeled "甲" and "乙", sitting on a horizontal surface. Container 甲 has vertical sides and a rectangular base. Container 乙 has outward-sloping sides, wider at the top than the bottom, and a rectangular base (same size as 甲). Both containers contain liquid up to the same level. Dotted lines are drawn inside container 甲 to indicate the liquid level.
**Handwritten Notes/Formulas:**
1. P=pgh pgh=p乙h乙 (Likely relates pressure, density, gravity, height, comparing 甲 and 乙)
2. m=PV体积 mp