KPK CLASS 10 PHYSICS
COMPLETE ORIGINAL REVISION NOTES — Q&A; +
NUMERICALS
English Medium | Chapters 10–18
Chapter 10 — Simple Harmonic Motion and Waves
Periodic and Oscillatory Motion
Periodic motion repeats after equal intervals. Oscillatory motion is to-and-fro motion about a mean position.
SHM
In simple harmonic motion, restoring force is directed toward the mean position and is proportional to displacement.
Important terms
Amplitude is maximum displacement. Time period T is time for one oscillation. Frequency f is oscillations per second.
Wavelength λ is distance between corresponding points of successive waves.
Wave types
Transverse: vibrations are perpendicular to propagation. Longitudinal: vibrations are parallel and form compressions and
rarefactions.
Q&A;
Q: What is SHM? A: It is oscillatory motion in which restoring force is proportional to displacement and directed toward the
mean position.
Q: What is frequency? A: Number of complete oscillations per second.
Numerical
Example: A body makes 20 oscillations in 5 s. f = N/t = 20/5 = 4 Hz; T = 1/f = 0.25 s.
Formulas
f = 1/T; v = fλ; for a simple pendulum at small amplitude, T = 2π√(l/g).
Quick Practice
1. Define the main terms of this chapter. 2. Write the important law/principle. 3. Write the relevant formula and its SI units. 4.
Solve the given numerical using: Given → Formula → Substitution → Answer with unit.
, Chapter 11 — Sound
Sound
Sound is produced by vibrating bodies and needs a material medium. In air, sound is longitudinal.
Characteristics
Pitch mainly depends on frequency; loudness mainly depends on amplitude; quality depends on waveform.
Q&A;
Q: What is an echo? A: Reflected sound heard separately from the original sound. Q: What is ultrasound? A: Sound with
frequency above about 20 kHz.
Numerical
Example: Sound travels 680 m in 2 s. v = d/t = 680/2 = 340 m/s.
Formula
v = fλ; speed = distance/time.
Quick Practice
1. Define the main terms of this chapter. 2. Write the important law/principle. 3. Write the relevant formula and its SI units. 4.
Solve the given numerical using: Given → Formula → Substitution → Answer with unit.
COMPLETE ORIGINAL REVISION NOTES — Q&A; +
NUMERICALS
English Medium | Chapters 10–18
Chapter 10 — Simple Harmonic Motion and Waves
Periodic and Oscillatory Motion
Periodic motion repeats after equal intervals. Oscillatory motion is to-and-fro motion about a mean position.
SHM
In simple harmonic motion, restoring force is directed toward the mean position and is proportional to displacement.
Important terms
Amplitude is maximum displacement. Time period T is time for one oscillation. Frequency f is oscillations per second.
Wavelength λ is distance between corresponding points of successive waves.
Wave types
Transverse: vibrations are perpendicular to propagation. Longitudinal: vibrations are parallel and form compressions and
rarefactions.
Q&A;
Q: What is SHM? A: It is oscillatory motion in which restoring force is proportional to displacement and directed toward the
mean position.
Q: What is frequency? A: Number of complete oscillations per second.
Numerical
Example: A body makes 20 oscillations in 5 s. f = N/t = 20/5 = 4 Hz; T = 1/f = 0.25 s.
Formulas
f = 1/T; v = fλ; for a simple pendulum at small amplitude, T = 2π√(l/g).
Quick Practice
1. Define the main terms of this chapter. 2. Write the important law/principle. 3. Write the relevant formula and its SI units. 4.
Solve the given numerical using: Given → Formula → Substitution → Answer with unit.
, Chapter 11 — Sound
Sound
Sound is produced by vibrating bodies and needs a material medium. In air, sound is longitudinal.
Characteristics
Pitch mainly depends on frequency; loudness mainly depends on amplitude; quality depends on waveform.
Q&A;
Q: What is an echo? A: Reflected sound heard separately from the original sound. Q: What is ultrasound? A: Sound with
frequency above about 20 kHz.
Numerical
Example: Sound travels 680 m in 2 s. v = d/t = 680/2 = 340 m/s.
Formula
v = fλ; speed = distance/time.
Quick Practice
1. Define the main terms of this chapter. 2. Write the important law/principle. 3. Write the relevant formula and its SI units. 4.
Solve the given numerical using: Given → Formula → Substitution → Answer with unit.
