Fluid and Conservation Laws: 2026-08-21 00:32:18

physics/Fluids/Fluid and Conservation Laws.md

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+[[Fluids]]
+
+# Summary
+* Pressure difference between fluids causes flow.
+* $A_1v_1=A_2v_2$ expresses conservation of mass. Narrow area force faster speeds to incompressible fluids.
+* Bernoulli's equation: $P_1+pgy_1+\frac{1}{2}pv_1^2=P_1+pgy_2+\frac{1}{2}pv_2^2$ expresses conservation of energy along a streamline.
+* Faster fluid has lower pressure and vice versa
+* Torricelli's theorem: $v=\sqrt{2g\Delta y}$ is derived from energy conservation and gives exit speed of draining fluid.
+* Assume fluids are ideal unless stated otherwise.

physics/Fluids/Fluid and Newton Laws.md

@@ -1 +1,8 @@
-[[Fluids]]
+[[Fluids]]
+
+# Summary
+* Fluid particles obey Newton laws.
+* Buoyant force is a net upwards force on an object in a fluid, caused by pressure and increases with depth.
+* Buoyant force equals weight of fluid displaced: $F_b=pVg$ where p is fluid density and V is displaced volume.
+* For a floating object, buoyant force equals the object's weight: $V_{submerged}/V=p_{object}/P_{fluid}$
+* Object floats when density is less than fluids and sinks when it's greater.

physics/Physics AP Exam Tips.md

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+[[Physics]]
+* Assume fluids are ideal unless stated otherwise.

physics/Torque and Rotational Dynamics/Rotational Inertia.md

@@ -8,6 +8,7 @@ Several discrete objects:
 $$I_{tot}=\Sigma I_i=\Sigma m_i r^2$$
 
 # Parallel Axis Theorem
+Essentially shifting the axis and calculating the new inertia.
 $$I'=I_{cm}+Md^2$$
 - $I$' is rotational inertia about the parallel axis (kg⋅m²)
 - $I_{cm}$ is rotational inertia about the center-of-mass axis (kg⋅m²)