A block of mass $1 kg$ is suspended by a string of mass $1 kg$, length $1 m$ as shown in figure. $(g=10\,m /$ $s ^2$ ) Calculate: The tension in string at its lowest point.

A football of radius $R$ is kept on a hole of radius $r (r < R)$ made on a plank kept horizontally. One end of the plank is now lifted so that it gets tilted making an angle $\theta$ from the horizontal as shown in the figure below. The maximum value of $\theta$ so that the football does not start rolling down the plank satisfies (figure is schematic and not drawn to scale) -

Resultant of action and reaction is zero. (True or False)

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

As shown in figure, a $70\,kg$ garden roller is pushed with a force of $\overrightarrow{ F }=200\,N$ at an angle of $30^{\circ}$ with horizontal. The normal reaction on the roller is $.......\,N$ $\left(\right.$ Given $\left.g =10\,m s ^{-2}\right)$

Three blocks $A$, $B$ and $C$ are pulled on a horizontal smooth surface by a force of $80 \mathrm{~N}$ as shown in figure

The tensions $T_1$ and $T_2$ in the string are respectively