SHMHard
Question
Three simple harmonic motion in the same direction having the same amplitude and same period are suspended. If each differ in phase from the next by 45o, then
Options
A.the resultant amplitude is ( 1 + √2)α
B.the phase of the resultant motion relative to the first is 90o
C.the energy associated with the resulting motion is (3 + 2 √2) times the energy associated with any single motion
D.(d) the resulting motion is not simple harmonic
Solution
From superposition priciple
y = y1 + y2 + y3
= a sin ωt + a sin (ωt + 45o) + a sin (ωt + 90o)
= a[ sin ωt + sin (ωt + 90o)] + a sin (ω + 45o)
= 2a sin (ωt + 45o) cos 45o + a sin (ωt + 45o)
= (√2 + 1) a sin (ωt + 45o) = A sin (ωt + 45o)
Therefore, resultant motion is simple harmonic of amplitude
A = (√2 + 1)a
and which differ in phase by 45o relative to the first.
Energy in SHM ∝ (amplitude)2 [E =
mA2 ω2]
∴
=
= (√2 + 1)2 = (3 + 2√2)
∴ Eresultant = (3 + 2√2) Esingle
y = y1 + y2 + y3
= a sin ωt + a sin (ωt + 45o) + a sin (ωt + 90o)
= a[ sin ωt + sin (ωt + 90o)] + a sin (ω + 45o)
= 2a sin (ωt + 45o) cos 45o + a sin (ωt + 45o)
= (√2 + 1) a sin (ωt + 45o) = A sin (ωt + 45o)
Therefore, resultant motion is simple harmonic of amplitude
A = (√2 + 1)a
and which differ in phase by 45o relative to the first.
Energy in SHM ∝ (amplitude)2 [E =
mA2 ω2]∴
=
= (√2 + 1)2 = (3 + 2√2)∴ Eresultant = (3 + 2√2) Esingle
Create a free account to view solution
View Solution FreeMore SHM Questions
For a SHM with given angular frequency, two arbitrary initial conditions are necessary and sufficient to determine the m...The motion of a particle executing simple harmonic motion is described by the displacement function, x(t) = A cos (ω...Two particles execute S.H.M. along the same line at the same frequency. They move in opposite direction at the mean posi...A simple pendulum of length L has an energy E and amplitude A. The energies of the simple pendulum (i) when the length i...Figure shows a mass m suspended with a massless inextensible string passing over a frictionless pulley. The other end of...