Question

Figure B1.1 shows a girl, standing 150 m in front of tall building while firing a shot using a starting pistol. A boy, standing 350 m from the girl, hears two bangs 1 s apart.why does the boy hear two bangs

Answer 1

Given:

A girl standing 150 m in front of tall building while firing a shot using a starting pistol. A boy, standing 350 m from the girl, hears two bangs 1 s apart.

To explain:

Why the boy heard two sounds?

Explaination:

• Let us consider that the boy is standing in the left side of girl and the building is on the right side of the girl.

• Now , when the girl fires a shot from the gun , sound wave generated from the gun travel both towards the boy as well as the building.

• So, the boy initially hears one sound.

• The other sound wave(towards the building) undergoes reflection from building surface and then returns back towards the boy.

• So, the boy hears the second sound 1 sec later.

Refer to attached diagram.