The travel velocity of these two wave types is not the same (P-waves are faster than S-waves). Thus, if there is an earthquake somewhere, the first waves that arrive are P-waves. In essence, the gap in P-wave and S-wave arrival gives a first estimate of the distance to the earthquake.
With the mysterious U.S. Senator Eddie Morra (Bradley Cooper) providing him with a second drug to counteract NZT's deadly side effects, Brian uses his enhanced abilities to help FBI agent Rebecca Harris (Jennifer Carpenter).
In fact, other than Jason David Frank (a.k.a. the Green Ranger) implying he might cameo, none of the original Mighty Morphin' actors are expected to appear in the reboot. As one of the five original Mighty Morphin' Power Rangers, Amy Jo Johnson played Kimberly in 138 episodes of the show. She departed the show in 1995, and actress Catherine Sutherland was brought in to play Kat, the new Pink Ranger. Johnson reprised Kimberly one more time in 1997's Turbo: A Power Rangers Movie, but she hasn't made any appearances in the franchise since, although she continues to appear at fan conventions.