Question

A Man is lying on the floor of a large empty hemisphere 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 0.2s. What is radius of the ball?Speed of sound in water=1480m/s

Answer 1

The answer of this question is 148m.

Distance = Velocity×Time/2.

D= 1480×2/2×10 (So 2 and 2 cancel and 10 and 0 of 1480 cancel.)

So answer is 148m