Calibration Bar: A round bar of steel approximately 3 feet in length, weighing over 8 pounds and having a diameter of exactly 1 inch
L = 3. 016 feet
w = 8.163 pounds, m = 8.163/32.1740 = 0. 2537 slugs
d = 1.000 inch, r = 0.5000 inches = 0.04167 feet
I1 = (1/12)(0.2537)(3x0.04167x0.04167+3.016x3.016)
= 0.1924 slug-ft^2
Pendulum Properties: The average periods for the calibration bar on the pendulum and for the empty cradle are t1 = 4.62 seconds and t2 = 1.21 seconds
k = 0.1924 / [( 4.62 / 2Pi )^2 - ( 1.21 / 2Pi )^2] = 0.382
Ip = 0.382 ( 4.62 / 2Pi )^2 - 0.1924 = 0.014 slug-ft^2
The average period for the gun on the pendulum is t = 4.08 seconds
Ig = 0.382 x ( 4.08 / 2 x Pi )^2 - 0.014 = 0.147 slug-ft^2