Due to a technical malfunction a space explorer had to crash land on Planet-X. She manages to fix her space ship and now she is preparing for launch. However she needs to know the gravitational acceleration on the surface of the planet in order to take off successfully. She builds a mathematical pendulum out of a piece of string and a left over steel bolt. The bolt has a mass of 45.7 g, and the string is 145 cm long. She attaches the pendulum to a fixed point and she lets it swing. She counts 15 complete oscillations in a time period of 57.1 seconds. What is the gravitational acceleration on the surface of Planet-X