13. Let V and W be two objects on a straight track, both starting at the same position at time t = 0. Let v(t) = sin(t) and w(t) = sin (t) describe their respective velocities at time t. (a) Describe in one to three sentences what physical quantity is represented T by (v(t) - w(t) ) dt. (b) What maximum distance between the two objects is achieved before the distance between them starts to decrease (for the first time)? Explain your answer carefully