Topic 6: One-Page Revision Sheet

Chapter 10: Oscillations – One Page Revision

1. Oscillatory Motion

Motion in which a body moves to and fro about a fixed mean position repeatedly.

2. Mean Position

The fixed position about which oscillation takes place.

3. Periodic Motion

Motion which repeats itself after equal intervals of time.

4. Simple Harmonic Motion (SHM)

A motion in which restoring force is directly proportional to displacement from mean position and acts towards it.

Mathematical form:
F = −k x

5. Characteristics of SHM

• Motion is periodic
• Velocity is maximum at mean position
• Acceleration is maximum at extreme positions
• Restoring force always acts towards mean position

6. Time Period and Frequency

Time period (T): Time for one complete oscillation
Frequency (f): Number of oscillations per second

Relation:
f = 1 / T

7. Time Period Formulas

• Mass–spring system:
  T = 2π √(m / k)
• Simple pendulum:
  T = 2π √(L / g)

8. Simple Pendulum

• Consists of light inextensible string and heavy bob
• Performs SHM for small oscillations
• Time period depends on length and gravity
• Independent of mass of bob

9. Energy in SHM

Kinetic Energy:
KE = (1/2) m v²
Maximum at mean position

Potential Energy:
PE = (1/2) k x²
Maximum at extreme positions

Total Energy:
E = (1/2) k A² (constant)

10. Important CET Points

• Definition and characteristics of SHM
• Identification of mean and extreme positions
• Time period formulas of pendulum and spring
• Energy distribution in SHM
• Concept-based MCQs + numericals