- ⭐ – Most used in JEE
- ⚠️ – Common Mistake
- 💡 – Memory Hint
Basic Definition of SHM
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| SHM Condition | [a = -\omega^2 x] | [a] = acceleration, [\omega] = angular frequency, [x] = displacement | m/s² | Defining equation of SHM ⭐ |
| Angular Frequency | [\omega = 2\pi f] | [f] = frequency | rad/s | Basic relation ⭐ |
| Time Period | [T = \dfrac{2\pi}{\omega}] | [T] = time period | s | Inverse of frequency |
| Frequency | [f = \dfrac{1}{T}] | — | Hz | Cycles per second |
💡 Memory Hint:
SHM → restoring force proportional to displacement
Displacement, Velocity, Acceleration
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Displacement | [x = A\sin(\omega t + \phi)] | [A] = amplitude, [\phi] = phase constant | m | General SHM equation ⭐ |
| Velocity | [v = \omega\sqrt{A^2 – x^2}] | [v] = velocity | m/s | Max at mean position ⭐ |
| Acceleration | [a = -\omega^2 x] | — | m/s² | Opposite direction ⚠️ |
| Maximum Velocity | [v_{max} = A\omega] | — | m/s | At mean position ⭐ |
| Maximum Acceleration | [a_{max} = A\omega^2] | — | m/s² | At extreme position ⭐ |
💡 Memory Hint:
- Mean → velocity max
- Extreme → acceleration max
Energy in SHM
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Total Energy | [E = \dfrac{1}{2}kA^2] | [k] = force constant | J | Constant ⭐ |
| Kinetic Energy | [K = \dfrac{1}{2}k(A^2 – x^2)] | — | J | Max at mean position |
| Potential Energy | [U = \dfrac{1}{2}kx^2] | — | J | Max at extreme ⭐ |
💡 Memory Hint:
Energy shifts between KE ↔ PE
Time Period of SHM Systems
Spring-Mass System
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Time Period | [T = 2\pi\sqrt{\dfrac{m}{k}}] | [m] = mass, [k] = spring constant | s | Most important ⭐ |
Simple Pendulum
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Time Period | [T = 2\pi\sqrt{\dfrac{l}{g}}] | [l] = length, [g] = gravity | s | Independent of mass ⭐ |
| Frequency | [f = \dfrac{1}{2\pi}\sqrt{\dfrac{g}{l}}] | — | Hz | Derived form |
💡 Memory Hint:
Pendulum → depends only on length & gravity
Phase & Phase Difference
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Phase | [\theta = \omega t + \phi] | [\theta] = phase | rad | Position in cycle |
| Phase Difference | [\Delta \phi = \omega \Delta t] | — | rad | Time shift relation ⭐ |
💡 Memory Hint:
Phase tells where particle is in motion
Relation with Circular Motion
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| SHM Projection | Projection of circular motion | — | — | Key concept ⭐ |
| Velocity Relation | [v = \omega\sqrt{A^2 – x^2}] | — | m/s | Derived from circle |
💡 Memory Hint:
SHM = projection of uniform circular motion
Important Relations
| Concept | Formula | Symbols Meaning | SI Units | Key Notes / Tricks |
|---|---|---|---|---|
| Force | [F = -kx] | [F] = restoring force | N | Hooke’s law ⭐ |
| Angular Frequency | [\omega = \sqrt{\dfrac{k}{m}}] | — | rad/s | Derived from motion ⭐ |
| Acceleration Relation | [a = -\omega^2 x] | — | m/s² | Core identity |
💡 Memory Hint:
Everything revolves around [\omega]