Force Vectors: (Scalar and vectors, vector addition of forces, addition of system of coplanar forces, Cartesian vectors, Addition and subtraction of Cartesian vectors, Force vector directed along a line and Dot product), Equilibrium of particle : (Condition for the equilibrium of particle, The free-body diagram and Coplanar force system), Force system resultant : (Moment of a force-scalar formulation, Cross product, Moment of force – vector formulation, Moment of force about a specified axis and Moment of couple), Center of gravity: (Center of gravity and center of mass for a system of particle and centre of gravity of a mass supported by single point lies vertically above the point of support.