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To hear a clear echo, the reflecting surface should be at least ________ meters away from the source of sound.

To hear a clear echo, the reflecting surface should be at least ________ meters away from the source of sound.

واضح گونج سننے کے لیے، عکاسی کرنے والی سطح کو آواز کے منبع سے کم از کم کتنے میٹر دور ہونا چاہیے؟
Explanation
  • For a clear echo, the reflected sound must reach the ear at least 0.1 seconds after the original sound.

  • Since the speed of sound in air is about 343 m/s, the minimum required distance is 17 meters (343 × 0.1 / 2).