Two simple pendulums whose lengths are $100 \ cm$ and $121 \ cm$ are suspended side by side. Their bobs are pulled together and then released. After how many minimum oscillations of the longer pendulum,will the two be in phase again?

The time period of a simple pendulum inside a stationary lift is $T$. When the lift starts accelerating upwards with an acceleration of $\frac{g}{3}$,the time period of the pendulum will be

If two persons sit on a swing instead of one,why does the time period not change?

The time period of a seconds pendulum is $2\, s$. The spherical bob,which is empty from inside,has a mass of $50\, g$. This is now replaced by another solid bob of the same radius but with a mass of $100\, g$. The new time period will be ..... $s$.

The bob of a simple pendulum of length $L$ has a mass $m$ and charge $q$. The pendulum is suspended between the plates of a charged parallel plate capacitor. The direction of the electric field is shown in the figure. The period of oscillations of the simple pendulum is (acceleration due to gravity $g > qE/m$):

$A$ simple pendulum is released from rest at the horizontally stretched position. When the string makes an angle $\theta$ with the vertical,the angle $\phi$ which the acceleration vector of the bob makes with the string is given by