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Formula Quick Reference

A single-page cheat-sheet of every governing equation used across the 18 experiments, grouped the same way as the main Contents. Use this page while doing calculations so you don't have to open each experiment page individually — click the linked experiment name if you need the full derivation or context.

Rotational Dynamics

1. Bifilar Suspension

\[ T = 2\pi\sqrt{\dfrac{I l}{Mgb^{2}}} \qquad I = \dfrac{M g b^{2} T^{2}}{4\pi^{2} l} \]

2. Torsional Pendulum

\[ C = \dfrac{\pi\eta r^{4}}{2l} \qquad I = \dfrac{2md^{2}T^{2}}{T'^{2}-T^{2}} \qquad \eta = \dfrac{8\pi l I}{r^{4}T^{2}} \]

3. Flywheel

\[ \omega = \dfrac{2\pi n_{1}}{t} \qquad I = \dfrac{mr^{2}(2gh-\omega^{2}r^{2})}{\omega^{2}}\times\dfrac{n_{2}}{n_{1}+n_{2}} \]

4. Compound (Bar) Pendulum

\[ T = 2\pi\sqrt{\dfrac{k^{2}+h^{2}}{gh}} \qquad h_{1}h_{2}=k^{2} \qquad g = \dfrac{4\pi^{2}L}{T^{2}} \]

Elasticity of Solids

5. Non-Uniform (Cantilever) Bending

\[ Y = \dfrac{4Wl^{3}}{bd^{3}y} \]

6. Uniform Bending

\[ Y = \dfrac{3Mga l^{2}}{2bd^{3}e} \]

7. Searle's Apparatus

\[ Y = \dfrac{MgL}{\pi r^{2} l_{\text{ext}}} \]

8. Static Torsion

\[ \theta = \dfrac{2Cl}{\pi\eta r^{4}} \qquad \eta = \dfrac{2Cl}{\pi r^{4}\theta} \]

Fluid Properties: Viscosity & Surface Tension

9. Poiseuille's Method

\[ \eta = \dfrac{\pi P r^{4} t}{8Vl}, \qquad P=\rho g h \]

10. Stokes' Method

\[ \eta = \dfrac{2}{9}\dfrac{r^{2}g(\rho-\sigma)}{v} \]

11. Capillary Rise

\[ T = \dfrac{h r \rho g}{2} \]

Oscillations, Damping & Acoustic Methods (PG)

12. Coupled Pendulums

\[ f_{s}=\dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}} \qquad f_{a}=\dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}+\dfrac{2k}{m}} \qquad T_{\text{beat}}=\dfrac{1}{f_{a}-f_{s}} \]

13. Damped Oscillations

\[ A_{n}=A_{0}e^{-\gamma t} \qquad \delta = \ln\!\left(\dfrac{A_{n}}{A_{n+1}}\right)=\gamma T \qquad Q\approx\dfrac{\pi}{\delta} \]

14. Forced Oscillations & Resonance

\[ A(\omega)=\dfrac{F_{0}/m}{\sqrt{(\omega_{0}^{2}-\omega^{2})^{2}+(2\gamma\omega)^{2}}} \qquad Q=\dfrac{f_{0}}{\Delta f} \]

15. Ultrasonic Interferometer

\[ \lambda = 2\overline{\Delta d} \qquad v=f\lambda \qquad \beta=\dfrac{1}{\rho v^{2}} \qquad K=\rho v^{2} \]

Practical Applications

16. Ballistic Pendulum

\[ v = \dfrac{M+m}{m}\sqrt{2gh} \qquad 1-\cos\theta = \dfrac{m^{2}v^{2}}{2gL(M+m)^{2}} \]

17. Rolling Race on an Incline

\[ a = \dfrac{g\sin\theta}{1+k} \qquad I = kmr^{2} \qquad t = \sqrt{\dfrac{2L}{a}} \]

18. Gyroscopic Precession

\[ L = I\omega = \tfrac{1}{2}MR^{2}\omega \qquad \tau = Mgd \qquad \Omega = \dfrac{\tau}{L} = \dfrac{2gd}{R^{2}\omega} \]