P is the centre of mass of four point masses A,B, C and D which are lying in the same length but not along the same straight line then.

Take four points A, B, C and D such that A B, C lie on the same line and D is not on it. Can the four line segments overline AB , overline BC , overline CD , and overline AD from a quadrilateral? Give reason.

There are 15 points in a plane, no three of which are in the same straight line with the exception of 6, which are all in the same straight line. Find the number of i. straight lines formed, ii. number of triangles formed by joining these points.

There are 15 points in a plane, no three of which are in the same straight line with the exception of 6, which are all in the same straight line. Find the number of i. straight lines formed, ii. number of triangles formed by joining these points.

Given p points in a plane, no three of which are collinear q of these Points, which are in the same straight line. Determine the number of (I) straight lines

Show that centre of mass of an isolated system moves with a uniform velocity along a straight line path.