In the Olympiad of 700 BCE, athletes competing in the standing long jump used handheld weights called halters to lengthen their jumps. The weights were swung up in front just before liftoff and then thrown backward during the flight. Suppose a 78 kg athlete uses two 5.50 kg halters, throwing them horizontally to the rear at his maximum height. Let his liftoff velocity be V ?=(9.5i ?+4.0j ? ) m?s with or without the halters, and assume that he lands at the liftoff level. What distance would the use of the halters add to his range?