A man is lying on the floor of a large, empty hemispherical hall, in such a way that his head is at the centre of the hall. He shouts “Hello!” and hears the echo of his voice after 0.2 s. What is the radius of the hall? (Take speed of sound = 340 m/s)

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Solution

Given,
Time period $T = 0.2 S e c$
Velocity $V = 340 m / s$
Radius of the hall $d = ?$

Total distance travelled by the sound wave = 2.d
Hence, $2 d = V t$
=> $d = \frac{390}{2} \times 210 = 39 m$
Hence, Radius of hemispherical hall is 39m

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A man is lying on the floor of a large, empty hemispherical hall, in such a way that his head is at the centre of the hall. He shouts “Hello!” and hears the echo of his voice after 0.2 s. What is the radius of the hall? (Take speed of sound = 340 m/s)

Given, Time period T=0.2Sec Velocity V=340m/s Radius of the hall d=? Total distance travelled by the sound wave = 2.d Hence, 2d=Vt => d=3902×210=39m Hence, Radius of hemispherical hall is 39m

Given,
Time period $T = 0.2 S e c$
Velocity $V = 340 m / s$
Radius of the hall $d = ?$

Total distance travelled by the sound wave = 2.d
Hence, $2 d = V t$
=> $d = \frac{390}{2} \times 210 = 39 m$
Hence, Radius of hemispherical hall is 39m