The 790,000-lb jetliner a has four engines, each of which produces a nearly constant thrust of 30,000 lb during the takeoff roll. a small commuter aircraft b taxis toward the end of the runway at a constant speed vb = 19 mi/hr. determine the velocity and acceleration which a appears to have relative to an observer in b 11 seconds after a begins its takeoff roll. neglect air and rolling resistance.