00:01
So in this question we're told that for particle a, we have a position vector, ra is cos t in the i direction.
00:09
And for particle b, sorry, that's a terrible b, particle b, we have that its location vector is sine t in the j direction.
00:22
Now we're told that particles c and d have the same directions as a and b, but they're decaying towards the origin.
00:31
So what that means is that c has a position vector, rc, is cos t, e to the minus kt, i.
00:44
So it's just the a position vector scaled by this factor here.
00:49
And d, we're told, is the same as the b position vector, but scaled by the same factor as well.
00:55
So sine t, e to minus kt, j.
00:59
So now we want to find the relative velocity of c and d...