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.
As shown in figure, three forces $\mathrm{F}_{1}, \mathrm{~F}_{2}, \mathrm{~F}_{3}$ act at point $\mathrm{P}$ on body.
$(a)$ Figure shows that forces are in same plane that is forces are coplaner. Body moves with constant uniform speed (velocity).
$\therefore a =0$
$\mathrm{~F} =m a$
$=m(c)$
$=0$
$\therefore \overrightarrow{\mathrm{F}}_{1} +\overrightarrow{\mathrm{F}}_{2}+\overrightarrow{\mathrm{F}}_{3}=0$
$(b)$ Calculating torque of these forces about point$ P$. As forces passes through$ P$ torque about point $\mathrm{P}$ is zero.
Define $SI$ unit of force $N$. Define $CGS$ unit of force dyne.
Two masses $M$ and $m$ are connected by a weightless string. They are pulled by a force $F$ on a frictionless horizontal surface., the acceleration of mass $m$ is
The horizontal acceleration that should be given to a smooth inclined plane of angle $sin^{-1}\, (1/l)$ to keep an object stationary on the plane relative to the inclined plane is
A block of $\sqrt{3}\,kg$ is attached to a string whose other end is attached to the wall. An unknown force $F$ is applied so that the string makes an angle of $30^{\circ}$ with the wall. The tension $T$ is $...........\,N$ :(Given $g =10\,ms ^{-2}$ )
Describe Galileo’s experiment of inclined plane regarding motion.