As shown in figure the tension in the horizontal cord is $30 \,N$. The weight $W$ and tension in the string $OA$  in Newton are

One end of a string of length $l$ is connected to a particle of mass $m$ and the other to a small peg on a smooth horizontal table. If the particle moves in a circle with speed $v$ the net force on the particle (directed towards the centre) is :

$(i) \;T,$ $(ii)\; T-\frac{m v^{2}}{l},$ $(iii)\;T+\frac{m v^{2}}{l},$ $(iv) \;0$

$T$ is the tension in the string. [Choose the correct alternative].

In the figure shown, $A$ & $B$ are free to move. All the surfaces are smooth. then $(0 < \theta < 90^o)$

A small child tries to move a large rubber toy placed on the ground. The toy does not move but gets deformed under her pushing force $F$, which is obliquely upward as shown in the figure.Then, 

For given systen $T_2$ ....... 

The restoring force of a spring with a block attached to the free end of the spring is represented by