 The position of a particle is defined as the coordinate vector from the origin of a coordinate frame to the particle.For example, consider a tower 50 m south from your home, where the coordinate frame is centered at your home, such that east is in the direction of the x-axis and north is in the direction of the y-axis, then the coordinate vector to the base of the tower is r = (0, −50, 0).If the tower is 50 m high, and this height is measured along the z-axis, then the coordinate vector to the top of the tower is r = (0, −50, 50).