A person on Earth observes two rockets A and B directly approaching each other with speed 0.8c and 0.6c respectively. At a time when the distance between the rockets is observed to be 4.2 105m, the clocks of the rockets and the Earth are synchronized to t = 0s. The time of collision (in seconds ) of the rockets as measured in rocket A's frame is 10 What is x? [JEST 20181