7) A boomerang is thrown by a person in the open space, the person observes its journey in the air for an elapsed time of 2.5 seconds. Its initial "7," and final position "7," of observation are: 7: = 5.00 mi + 7.00 m j + 3.00 m k ; and if = -2.00 mi - 6.50 m j + 4.00 m k What is the average velocity with which the boomerang has travelled during elapsed time of observation