How would you solve this Physics problem regarding simple harmonic motion?

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.

Graph: http://imgur.com/MdAaB

Answer the following questions:
a) What is the period and frequency of the pendulum’s motion?
b) How many seconds out of phase with the displacements shown would graphs of the velocity and acceleration be?
c) What is the acceleration due to gravity on the surface of the planet in m/s^2? Determine the number of g-forces.
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Question

How would you solve this Physics problem regarding simple harmonic motion?

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.

Graph: http://imgur.com/MdAaB

Answer the following questions:
a) What is the period and frequency of the pendulum’s motion?
b) How many seconds out of phase with the displacements shown would graphs of the velocity and acceleration be?
c) What is the acceleration due to gravity on the surface of the planet in m/s^2? Determine the number of g-forces.
SHOW WOR