Physics
Two persons A and B are standing in front of a cliff in the same line 170 m apart as shown in the diagram.
Person B fires the gun and hears the echo in 3 s. Then the person A standing in front of the person B fires the gun.
(Speed of sound in air is 340 m s-1)
(a) Calculate:
- the distance of the person B from the cliff.
- the minimum time in which B hears the gunshot fired by A.
(b) Fill in the blank.
The echo is softer (less loud) than the original sound due to the decrease in …………… [amplitude / frequency] of the wave.
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