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 amplitude will be :

Two sound waves travel in the same direction in a medium . The amplitu

1.	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 amplitude will be :
Answer» `2 A` ` 3A` `sqrt(2)A` A Solution :Here `A_(1)=A,A_(2)=A, varphi=120^(@)` The amplitude of the RESULTING WAVE is `A_(R)=sqrt((A_(1))^(2)+(A_(2))^(2)+2A_(1)A_(2) cos varphi)` `=sqrt(A^(2)+A^(2)+2 A A cos 120^(@))` `= sqrt((A^(2)+A^(2)-A^(2)))=A ( :. cos120^(@)=-(1)/(2))`