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Krishna
2024-09-22 16:12:48 -05:00
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@@ -160,6 +160,54 @@ $$
k=\frac{||\vec{F}||}{x}
$$
# Buoyancy
![](https://openstax.org/apps/archive/20240812.170248/resources/890168a9ef96d6cdea88cf7a401fd7bd9618187a)
As shown in the image here, $||\vec{F}_B||$ is not simply equivalent to the weight (that's a force incorporating the force experienced because of gravity). Therefore, it's important to remember the more complicated formulas:
$$
F_1=h_1\rho gA
$$
$$
F_2=h_2\rho gA
$$
And the total magnitude of the buoyant force is simply the subtraction of the force pushing the object up and the force pushing the object down: $F_B=F_2-F_1$. Breaking apart these equations, it's important to understand a couple things:
- $\rho$, pronounced *rho* (the *h* is silent) is the density of the fluid. The SI unit for density is $\frac{\mathrm{kg}}{\mathrm{m}^3}$
- *Standard Temperature and Pressure* (STP) is the state of a system at $273.15$ K or $0\degree$ C, at $10^5$ ($1$ bar/$14$ atm) of pressure.
- At STP, the density of water, $\rho_w=0.9982071\approx 1$ g/ml
- A liter is a measure of volume equivalent to $0.001$ cubic meters, or 1000 cubic centimeters.
- $A$ is the cross sectional area of the object where the object is not parallel to the static particles of the liquid
> **Archimedes' Principle** \
> $F_B=w_{\mathrm{fl}}$, but you often need to break this down to really be able to calculate what's required.
## Fraction Submerged
The fraction of an object submerged can easily be found using the following equation:
$$
\frac{V_{\mathrm{sub}}}{V_{\mathrm{obj}}}=\frac{V_{\mathrm{fl}}}{V_{\mathrm{obj}}}
$$
$V_{\mathrm{fl}}$ is the volume of fluid displaced, not the volume of fluid total.
$$
\frac{V_{\mathrm{fl}}}{V_{\mathrm{obj}}}=\frac{m_{\mathrm{fl}}/\rho_{\mathrm{fl}}}{m_{\mathrm{obj}}/\rho_{\mathrm{obj}}}
$$
The following is only true if the object floats:
$$
\frac{V_{\mathrm{fl}}}{V_{\mathrm{obj}}}=\frac{\rho_\mathrm{obj}}{\rho_\mathrm{fl}}
$$
# Circular motion
**TODO!**
[^1]: I'm working in radians here.
[^2]: This is latin.