Usain and Rudolf are running on a circular track of length 240 m. They start running from 2 different points on the track and run at speeds of u m/s and r m/s respectively. Usain is the faster runner. They meet each other for the first time after a time of 16s. They meet for the second time 40s after they start running. If Rudolf had started running in the opposite direction, the two run would have met for the first time after 40 seconds. Find the speed of Usain.