Two persons are holding a rope of negligible weight tightly at its ends so that it is horizontal. $A$ $15\, kg$ weight is attached to the rope at the mid-point,which now no longer remains horizontal. The minimum tension required to completely straighten the rope is

In the following figure,the object of mass $m$ is held at rest by a horizontal force $F$ as shown. The force exerted by the string on the block is

There are four forces acting at a point $P$ produced by strings as shown in the figure. Point $P$ is at rest. The forces $F_1$ and $F_2$ are respectively:

Two like parallel forces $20 \,N$ and $30 \,N$ act at the ends $A$ and $B$ of a rod $1.5 \,m$ long. The resultant of the forces will act at the point ........

$A$ body of mass $40 \,g$ is moving with a constant velocity of $2 \,cm/s$ on a horizontal frictionless table. The force on the table is ....... $dyne$.

$A$ ladder rests against a frictionless vertical wall,with its upper end $6 \, m$ above the ground and the lower end $4 \, m$ away from the wall. The weight of the ladder is $500 \, N$ and its center of gravity ($C$.$G$.) is at $1/3$ of its length from the lower end. The reaction force from the wall will be (in Newton):