Learning objective
Recognise simple harmonic motion and relate displacement, velocity and acceleration.
CLASS 11 PHYSICS
Oscillations
Describe repeated motion about an equilibrium position.
State Board to NCERT bridge
From a swinging pendulum or spring to a mathematical model of periodic motion.
Tamil concept bridge
SHM-il acceleration eppodhum mean position-ai nokki irukkum; displacement-ukku opposite direction-il.
GUIDED LESSON
Learn the chapter step by step
Read one concept, explain it in your own words, then connect it to the formula or situation that follows. Do not try to memorise the chapter as isolated definitions.
A periodic motion repeats after a fixed time period. Amplitude is maximum displacement, while phase specifies the state of motion at an instant.
Tamil support: SHM-il acceleration eppodhum mean position-ai nokki irukkum; displacement-ukku opposite direction-il.
Ask yourself: Can I give one everyday example of periodic motion?
WORKED EXAMPLE
Restoring acceleration
Given: In SHM, a particle is displaced to the positive side of equilibrium.
- 1Use a = -omega^2 x.
- 2The minus sign gives the direction.
- 3Acceleration points back towards the mean position.
Answer: Acceleration is negative: it is a restoring acceleration.
FORMULA / FACT BANK
Know what each relationship means
SHM acceleration
a = -omega^2 x
Acceleration is opposite displacement.
Spring period
T = 2pi sqrt(m/k)
Mass-spring system.
Memory cue: amplitude · phase · time period · energy exchange
SELF-CHECK
Which concept should you start with?
Choose the core foundation concept for this chapter.
COMMON MISTAKES
- Do not use a formula before identifying the physical quantities and their SI units.
- Keep direction, sign convention and stated conditions visible throughout a solution.
- Check whether your answer has a sensible unit and magnitude.
REVISION PLAN
- 1. Re-read the visual summary and say each revision target aloud.
- 2. Redo the worked example without looking at the steps.
- 3. Complete the 80-question bank and revisit every incorrect explanation.
VISUAL NOTES
Oscillations at a glance
Periodic motion
Identify motion that repeats after equal time intervals.
Simple harmonic motion
Relate restoring force to displacement.
Energy in SHM
Track exchange between kinetic and potential energy.
Formula / fact focus
SHM acceleration
a = -omega^2 x
Spring period
T = 2pi sqrt(m/k)
Last-minute memory cues
- 1. ✓amplitude
- 2. ✓phase
- 3. ✓time period
- 4. ✓energy exchange
NEXT IN THIS CHAPTER
Practise this chapter with its complete 80-question MCQ bank, then use the video and revision notes to strengthen any weak areas.