Q19 of 54 Page 389

An echo is heard after 0.8 seconds, when a person fires a cracker 132.8 m from a high buildings. Calculate the speed of sound.

Given,


time for echo = 0.8 sec


height of building = 132.8 m


distance travelled by sound = 2×height


distance travelled = 2×132.8 = 265.6 m



More from this chapter

All 54 →
17

Illustrate with the help of an experiment that sound requires a medium to propagate.

 18

A sound wave of length 70 cm travels 840 m in 25 seconds. What is the velocity and frequency of sound?

 20

A source of wave produces, 40 crests and 40 troughs in 0.4 seconds. Find the frequency of the wave.

 21

Why an echo is not heard when distance between source of sound and reflecting body is 10 m?