Two sound waves travel in the same direction in a medium. The amplitude of each wave is A and the phase difference between the two waves is 120°. The resultant amptitude will be

Question

Two sound waves travel in the same direction in a medium. The amplitude of each wave is A and the phase difference between the two waves is 120°. The resultant amptitude will be (A) √2 A (B) 2A (C) 3A (D) 4A

Tardigrade Admin · Accepted Answer

R = √P2 + Q2 + 2 PQ cos2 θ = √A2 + A2 + 2A2 cos2 120° = A

Q. Two sound waves travel in the same direction in a medium. The amplitude of each wave is $A$ and the phase difference between the two waves is $12 0^{\circ}$ . The resultant amptitude will be

$2 A$

2A

3A

4A

A

$R = P^{2} + Q^{2} + 2 PQ co s^{2} θ$
$= A^{2} + A^{2} + 2 A^{2} co s^{2} 12 0^{\circ} = A$

Q. Two sound waves travel in the same direction in a medium. The amplitude of each wave is A and the phase difference between the two waves is 120∘. The resultant amptitude will be

2​A

2A

3A

4A

A

R=P2+Q2+2PQcos2θ​ =A2+A2+2A2cos2120∘​=A

Q. Two sound waves travel in the same direction in a medium. The amplitude of each wave is $A$ and the phase difference between the two waves is $12 0^{\circ}$ . The resultant amptitude will be

$2 A$

$R = P^{2} + Q^{2} + 2 PQ co s^{2} θ$
$= A^{2} + A^{2} + 2 A^{2} co s^{2} 12 0^{\circ} = A$