Question
A string fixed at one end is vibrating in its second overtone. The length of the string is $10\ cm$ and maximum amplitude of vibration of particles of the string is $2\ mm$ . Then the amplitude of the particle at $9\ cm$ from the open end is

Answer

Second overtone $\Rightarrow 5$ th harmonic

So, $\lambda=\frac{4 L}{5}=8 \mathrm{\,cm}$

$A_{s}=(2\, m m) \sin (k x)=(2\, m m) \sin \left(\frac{2 \pi}{\lambda} x\right)$

${=(2 \mathrm{\,mm}) \sin \left(\frac{2 \pi}{8 \mathrm{cm}} \times 1 \mathrm{cm}\right)} $

${=(2 \mathrm{\,mm}) \sin \left(\frac{\pi}{4}\right)=\sqrt{2} \mathrm{\,mm}}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In a steady state, the temperature at the end $A$ and $B$ of $20\,cm$ long rod $AB$ are $100\,^oC$ and $0\,^oC$ respectively. The temperature of a point $9\,cm$ from $A$ is....... $^oC$
The layers of atmosphere are heated through
In an experiment to determine the acceleration due to gravity $g$, the formula used for the time period of a periodic motion is $T=2 \pi \sqrt{\frac{7(R-r)}{5 g}}$. The values of $R$ and $r$ are measured to be $(60 \pm 1) \mathrm{mm}$ and $(10 \pm 1) \mathrm{mm}$, respectively. In five successive measurements, the time period is found to be $0.52 \mathrm{~s}, 0.56 \mathrm{~s}, 0.57 \mathrm{~s}, 0.54 \mathrm{~s}$ and $0.59 \mathrm{~s}$. The least count of the watch used for the measurement of time period is $0.01 \mathrm{~s}$. Which of the following statement($s$) is(are) true?

($A$) The error in the measurement of $r$ is $10 \%$

($B$) The error in the measurement of $T$ is $3.57 \%$

($C$) The error in the measurement of $T$ is $2 \%$

($D$) The error in the determined value of $g$ is $11 \%$

A particle of mass $m$ describes a circle of radius $r$. The centripetal acceleration of the particle is $4/r^2$. What will be the momentum of the particle?
An $LCR$ circuit is equivalent to a damped pendulum. In an $LCR$ circuit the capacitor is charged to $Q_0$ and then connected to the $L$ and $R$ as shown below.

If a student plots graphs of the square of maximum charge $( Q_{Max}  ^2 )$ on the capacitor with time$(t)$ for two different values $L_1$ and $L_2 (L_1 > L_2)$ of $L$ then which of the following represents this graph correctly? (plots are schematic and not drawn to scale)

Two concentric circular loops of radii $r _{1}=30\,cm$ and $r_{2}=50\,cm$ are placed in $X - Y$ plane as shown in the figure. $A$ current $I=7\,A$ is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately.
The specific heat at constant pressure of a real gas obeying $\mathrm{PV}^2=\mathrm{RT}$ equation is :
When a metal surface is illuminated by light of wavelengths $400\; nm$ and $250\; nm$, the maximum velocities of the photoelectrons ejected are $v$ and $2v$ respectively. The work function of the metal is $(h =$ Planck’s constant, $c =$ velocity of light in air)
A plane is revolving around the earth with a speed of $100\, km/hr $ at a constant height from the surface of earth. The change in the velocity as it travels half circle is.........$km/hr$
The expression $[M{L^2}{T^{ - 2}}]$ represents