A body of mass $60\,kg$ is suspended by means of three strings $P, Q$ and $R$ as shown in the figure is in equilibrium. The tension in the string $P$ is $..........g\,N$
$130.9$
$60$
$50$
$103.9$
Explain primary concept of force.
In the system shown in the adjoining figure, the tension $T_2$ is
Two equal heavy spheres, each of radius $r$, are in equilibrium within a smooth cup of radius $3 r$. The ratio of reaction between the cup and one sphere and that between the two sphere is
Explain main type of force with suitable example.