A body initially at rest undergoes rectilinear motion. The forcetime (F-t) graph for the motion of the body is given below. Find the linear momentum gained by the body in $$2 \mathrm{~s}$$.

Action and reaction can never balance out because

A stone of mass $$2 \mathrm{~kg}$$ is hung from the ceiling of the room using two strings. If the strings make an angle $$60^{\circ}$$ and $$30^{\circ}$$ respectively with the horizontal surface of the roof then the tension on the longer string is : $$g=10 \mathrm{~ms}^{-2}$$

If the resultant of all external forces acting on a system of particles is zero, then from an inertial frame one can surely say that