At the instant $t = 0$ a force $F = kt$ ( $k$ is a constant) acts on a small body of mass $m$ resting on a smooth horizontal surface. The time, when body leaves the surface is
$mg\,k\,sin\,\alpha $
$\frac{{k\,\sin \,\alpha }}{{mg}}$
$\frac{{mg\,\sin \,\alpha }}{{k}}$
$\frac{{mg}}{{k\,\sin \,\alpha }}$
A weight $M g$ is suspended from the middle of a rope whose ends are at the same level. The rope is no longer horizontal. The minimum tension required to completely straighten the rope is ......
A body of mass $5\,kg$ is suspended by a spring balance on an inclined plane as shown in figure. (in $N$)
There are three forces $\vec {F_1}$, $\vec {F_2}$ and $\vec {F_3}$ acting on a body, all acting on a point $P$ on the body. The body is found to move with uniform speed.
$(a)$ Show that the forces are coplanar.
$(b)$ Show that the torque acting on the body about any point due to these three forces is zero.
For given systen ${\theta _1}$ ....... $^o$
Which of the following groups of forces could be in equibrium