On your first trip to the Planet X you happen to take all along a 130 mass, a 40 cm long spring, a meter stick and a stopwatch. You are interested regarding the acceleration due to gravity on Planet X, where ordinary tasks seem simpler than on earth; however you cannot find this information in your Visitor's Guide. One night you hang the spring from the ceiling in your room and dangle the mass from it. You find that the mass stretches the spring by 23.1. You then pull the mass down 5.10 and release it. With the stop-watch you recognize that 11.0 oscillations take 17.5.