$A$ balloon of mass $M$ descends with an acceleration $a (< g)$. What mass needs to be removed from the balloon so that it starts ascending with acceleration $a$?

Three identical particles are joined together by a thread as shown in the figure. All the three particles are moving on a smooth horizontal plane about point $O$. If the speed of the outermost particle is $v_0$,then the ratio of tension in the three sections of the thread is:

Two particles each of mass $m$ are moving in horizontal circles with the same angular speed $\omega$. If both strings are of the same length $l$,find the ratio of tension in the strings $\frac{T_1}{T_2}$.

$T_1$ and $T_2$ in the given figure are

Two bodies of masses $10\; kg$ and $20\; kg$ respectively,kept on a smooth horizontal surface,are tied to the ends of a light string. $A$ horizontal force $F = 600\; N$ is applied to $(i)\; A$,$(ii)\; B$ along the direction of the string. What is the tension in the string in each case?

An elevator accelerates upwards at a constant rate. $A$ uniform string of length $L$ and mass $m$ supports a small block of mass $M$ that hangs from the ceiling of the elevator. The tension at distance $l$ from the ceiling is $T$. The acceleration of the elevator is