1. The problem statement, all variables and given/known data An astronaut has landed on Planet N-40 and conducts an experiment to determine the acceleration due to gravity on that planet. She uses a simple pendulum that is 0.640 m long and measures that 10 complete oscillations 26.0 s. What is the acceleration of gravity on Planet N-40? 2. Relevant equations I am not sure what to use. 3. The attempt at a solution I tried using T=2pi square root L/g and solve for g and plugged everything in. Period T I did 26/10 so 1 period every 2.6 seconds I got g=.595 and is non of the choices. It is this formula above. I solved for g wrong. Now I got the correct answer thank you everyone.