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Echo and Ranging
Send pulse, receive echo, calculate d=vt/2.
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Echo and Ranging
Recommended for Class 10
Echo and Ranging
Echoes can be used to measure distance.
A sound pulse is sent toward an object.
The sound reflects and returns.
If the travel time is measured and sound speed is known:
**distance = vt/2**
The factor 2 is necessary because the sound travels:
source → target → source.
Sonar
SONAR uses sound waves, often ultrasound, to detect underwater objects and measure depth or distance.
Worked Example
Ultrasound pulse returns after:
t = 0.10 s
Speed in water:
v = 1500 m/s
Distance:
d = vt/2
= 1500 × 0.102
= **75 m**
Echo and Ranging — Advanced
Common Mistakes
Common Mistakes
- Mistake
Never forget the round trip.
- Mistake
Use the correct sound speed for the medium.
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Practice
PQ
Q1. Define ranging.
PQ
Q2. Derive formula d=vt/2.
PQ
Q3. Define SONAR.
PQ
Q4. Calculate distance for t=0.10 s, v=1500 m/s.
PQ
Q5. Why does medium speed matter?
Exam Practice
EQ
Q1. Explain echo ranging.
EQ
Q2. Derive d=vt/2.
EQ
Q3. Explain SONAR.
EQ
Q4. Calculate an echo ranging distance.
EQ
Q5. Explain why correct medium speed is essential.
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.