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QJEEM24Phbb71: JEE Main 2024 Physics - Class 11 JEEM24Phbb71 Solution: The displacement of a particle executing SHM is given by . The…

The displacement of a particle executing SHM is given by x=10sin⁡(wt+π3)mx=10 \sin \left(w t+\frac{\pi}{3}\right) m . The time period of motion is 3.14 s3.14 \mathrm{~s} . The velocity of the particle at t=0t=0 is _______ m/s\mathrm{m} / \mathrm{s} .

Step-by-Step Verified Solution

The displacement of a particle executing Simple Harmonic Motion (SHM) can be expressed as:

x=Asin⁡(ωt+ϕ)x = A \sin(\omega t + \phi)

Where:

AA is the amplitude of the SHM,

ω\omega is the angular frequency,

tt is the time,

ϕ\phi is the phase constant (phase angle at t=0t = 0 ).

In the given equation, x=10sin⁡(ωt+π3)x = 10 \sin(\omega t + \frac{\pi}{3}) m, the amplitude A=10A = 10 m and the phase constant ϕ=π3\phi = \frac{\pi}{3} . The time period T=3.14T = 3.14 s is given, from which we can find the angular frequency ω\omega using the relationship:

ω=2πT\omega = \frac{2\pi}{T}

Substituting the given T=3.14T = 3.14 s:

ω=2π3.14≈2 rad/s\omega = \frac{2\pi}{3.14} \approx 2 \, \text{rad/s}

To find the velocity of the particle, we differentiate the displacement xx with respect to time tt . The derivative of the displacement gives the velocity:

v=dxdtv = \frac{dx}{dt}

So, for x=10sin⁡(ωt+π3)x = 10 \sin(\omega t + \frac{\pi}{3}) :

v=ddt[10sin⁡(ωt+π3)]v = \frac{d}{dt}[10 \sin(\omega t + \frac{\pi}{3})]

Applying differentiation, we get:

v=10ωcos⁡(ωt+π3)v = 10\omega \cos(\omega t + \frac{\pi}{3})

Plug in the value of ω=2\omega = 2 rad/s and evaluate it at t=0t = 0 to find the initial velocity:

v=10⋅2cos⁡(2⋅0+π3)v = 10 \cdot 2 \cos(2 \cdot 0 + \frac{\pi}{3})

v=20cos⁡(π3)v = 20 \cos(\frac{\pi}{3})

cos⁡(π3)=12\cos(\frac{\pi}{3}) = \frac{1}{2} , therefore:

v=20⋅12=10 m/sv = 20 \cdot \frac{1}{2} = 10 \, \text{m/s}

Thus, the velocity of the particle at t=0t = 0 is 1010 m/s.

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