Pls help :)

An astronaut lands on an alien planet. He places a pendulum (L = 0.200 m) on the surface and sets it in simple harmonic motion, as shown in this graph.
Answer the following questions:
What is the period and frequency of the pendulum’s motion?
How many seconds out of phase with the displacements shown would graphs of the velocity and acceleration be?
What is the acceleration due to gravity on the surface of the planet in ? Determine the number of g-forces.
Show any necessary calculations.