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Physical Tools

Mechanical engineering deals with the analysis and description of mechanical systems and phenomena based on physical principles. Therefore, understanding the underlying physical concepts and formulas is of crucial importance.

In technical mechanics, there are numerous physical concepts and formulas that are used in the analysis and description of mechanical systems.

Here you will find important physical formulas that are helpful for solving problems in technical mechanics.

Density of Substances in Physics

Density indicates the mass per unit volume of a substance.

$$ \begin{aligned} \varrho &= \dfrac{m}{V} \end{aligned} $$
Table 1: Mathematical symbols of the formula of density
Symbol Name Quantity Unit
\(\varrho\) Rho Density g/cm3, kg/m3, g/l
\(m\) Mass kg
\(V\) Volume m3

Unit conversion:

$$ \begin{aligned} 1 \dfrac{\mathrm{g}}{\mathrm{cm^3}} = 1 \dfrac{\mathrm{kg}}{\mathrm{dm^3}} = 1000 \dfrac{\mathrm{kg}}{\mathrm{m^3}}\\[10pt] 1 \dfrac{\mathrm{kg}}{\mathrm{m^3}} = 0,001 \dfrac{\mathrm{kg}}{\mathrm{dm^3}} = 0,001 \dfrac{\mathrm{g}}{\mathrm{cm^3}}\\ \end{aligned} $$

Density of selected substances in g/cm3 or 1000 kg/m3:

Table 2: Density of selected substances
Substance Density
Aluminum 2,710
Ice (at 0 °C) 0,917
Cast iron 7,250
Copper 8,960
Magnesium 1,738
Unalloyed steel 7,850
Water (at 0 °C) 1,000