The position vector of a body starting from a pointat
with constant velocity
at any time
is
If the body makes a change of course at any time
the position vector will not be given by this expression. We must take account of the change of course by finding the position vector at the instant when the course change takes place and using this as the new starting point
We must also take account of the fact that we are not now starting from this point at
If the change of course takes place at
and the new velocity vector is
the new position vector for
is given by
If several changes of course occur we must apply this procedure at each change of course and the expression for the position vector will only be valid until the next course change.
For
For
For
For