NEET-XII-Physics

12: Simple Harmonic Motion

with Solutions - page 2
Qstn# ii-11 Prvs-QstnNext-Qstn
  • #11
    The total mechanical energy of a spring-mass system in simple harmonic motion is
    E=12mω2A2.Suppose the oscillating particle is replaced by another particle of double the mass while the amplitude A remains the same. The new mechanical energy will
    (a) become 2E
    (b) become E/2
    (c) become
    2E
    (d) remain E
    digAnsr:   d
    Ans : (d) remain E
    Mechanical energy (E) of a spring-mass system in simple harmonic motion is given by,
    `` {E}_{}=\frac{1}{2}m{\omega }^{2}{A}^{2}``
    where m is mass of body, and
    `` \omega `` is angular frequency.
    Let m1 be the mass of the other particle and ω1 be its angular frequency.
    New angular frequency ω1 is given by,
    `` {\omega }_{1}=\sqrt{\frac{k}{{m}_{1}}}=\sqrt{\frac{k}{2m}}({m}_{1}=2m)``
    New energy E1 is given as,
    `` {E}_{1}=\frac{1}{2}{m}_{1}{\omega }_{1}^{2}{A}^{2}``
    `` =\frac{1}{2}\left(2m\right)(\sqrt{\frac{k}{2m}}{)}^{2}{A}^{2}``
    `` =\frac{1}{2}m{\omega }^{2}{A}^{2}=E``
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