Two collinear SHMs of equal amplitude A and equal angular frequency ω have a phase difference of 120°. If they are superposed, what is the amplitude of the resultant SHM?
Options

Question

Two collinear SHMs of equal amplitude A and equal angular frequency ω have a phase difference of 120°. If they are superposed, what is the amplitude of the resultant SHM?

G1 Physics · Accepted Answer

For two SHMs of equal amplitude A and phase difference δ, Aᵣ = √[A²+A²+2A²cosδ]. With δ = 120°, cos120° = −1/2. Therefore, Aᵣ = √[2A²−A²] = A. Correct option: B.