Three simple harmonic motions of equal amplitudes A and equal time periods in the same direction combine. The phase of the second motion is 60o ahead of the first and the phase of the third motion is 60° ahead of the second. Find the amplitude of the resultant motion.

2 A

let the S.H.Ms be

Resultant will be x =

Resultant amplitude between first two will be

R =

R =


= A

Resultant amplitude of all three S.H.Ms will be the resultant of R and

Let be the resultant of all three S.H.Ms then,

[ angle between will be 60° + 30° ]


= 2A