Two vectors P and Q act successively at a point.
(a) State the law of vector addition that relates the resultant of P and Q.
(b) With the help of a neat, labelled scale diagram, illustrate how this law is applied to obtain the resultant when P and Q act one after the other.
(c) Describe, with sketches, how the graphical procedure for subtracting Q from P differs from the procedure for adding the two vectors.