Solve Pendulum Problem: Indiana Jones Swinging at 17°

[Punchlinegirl]

Indiana Jones is swinging from a rope. The distance between the pivot point and his center of mass is 31.0 m. He begins swinging from rest at an angle \theta = 17.0 degrees. Assuming the Indiana and the rope can be treated as a simple pendulum, what is the value of \theta after 1.33s (in degrees)?

i have no idea where to begin on this problem. I know that the formula for a period of a pendulum is T= 2\pi \sqrt L/g , but i dont' know where the angle comes into play. Any help?

 

[Pyrrhus]

Use the solution to the differential equation

\ddot{\theta} + \omega^{2} \theta = 0

where \omega = \sqrt{\frac{g}{L}}

For this case you will need:

\theta (t) = \theta_{max} \cos (\omega t)

 

[Punchlinegirl]

ok i got it.. thanks