A pendulum bob has a speed of $3\, {m} / {s}$ at its lowest position. The pendulum is $50 \,{cm}$ long. The speed of bob, when the length makes an angle of $60^{\circ}$ to the vertical will be $ .......\,{m} / {s}$ $\left(g=10 \,{m} / {s}^{2}\right)$
JEE MAIN 2021, Medium
Download our app for free and get startedPlay store
Applylng work energy theorem

$w _{ g }+ w _{ T }=\Delta K$

$- mgl \left(1-\cos 60^{\circ}\right)=\frac{1}{2} mv ^{2}-\frac{1}{2} mu ^{2}$

$v ^{2}= u ^{2}-2 gl \left(1-\cos 60^{\circ}\right)$

$v ^{2}=9-2 \times 10 \times 0.5\left(\frac{1}{2}\right)$

$v ^{2}=4$

$v =2 m / s$

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    In forced oscillations, a particle oscillates simple harmonically with a frequency equal to
    View Solution
  • 2
    Consider the following statements. The total energy of a particle executing simple harmonic motion depends on its

    $(1)$ Amplitude      $(2) $ Period         $(3)$ Displacement

    Of these statements

    View Solution
  • 3
    A spring mass system preforms $S.H.M.$ If the mass is doubled keeping amplitude same, then the total energy of $S.H.M.$ will become :
    View Solution
  • 4
    The time period of a simple pendulum is $2\, sec$. If its length is increased $4$ times, then its period becomes  ..... $\sec$
    View Solution
  • 5
    When two displacements represented by $y_1 = asin\left( \omega t \right)$ and $y_2 = bcos\left(\omega t \right)$ are superimposed the motion is
    View Solution
  • 6
    Two, spring $P$ and $Q$ of force constants $k_p$ and ${k_Q}\left( {{k_Q} = \frac{{{k_p}}}{2}} \right)$ are stretched by applying forces of equal magnitude. If the energy stored in $Q$ is $E$, then the energy stored in $P$ is
    View Solution
  • 7
    A vertical mass-spring system executes simple harmonic oscillations with a period of $2\,s$. A quantity of this system which exhibits simple harmonic variation with a period of $1\, s$ is
    View Solution
  • 8
    A block of mass $0.1\, kg$ is connected to an elastic spring of spring constant $640\, Nm^{-1}$ and oscillates in a damping medium of damping constant $10^{-2}\, kg\,s^{-1}$ . The system dissipates its energy gradually. The time taken for its mechanical energy of vibration to drop to half of its initial value, is closest to ..... $s$
    View Solution
  • 9
    A particle executes simple hormonic motion between $x =\, -A$ and $x = +A$ . It starts from $x = 0$ moves in $+x-$ direction. The time taken for it to move from $x = 0$ to $x = \frac {A}{2}$ is $T_1$ and to move from $\frac {A}{2}$ to $\frac {A}{\sqrt 2}$ is $T_2$ , then
    View Solution
  • 10
    If displacement $x$ and velocity $v$ are related as $4v^2 = 16\, -\, x^2$ in a $SHM$ . Then time period of given $SHM$ is (consider $SI\,units$ )
    View Solution