The acceleration of the mass center is 
and the angular acceleration of the beam at this instant, 
The mass moment of inertia of the beam :
Thus Ig = 1/2 ml^2
this implies Ig = 1/2 ( 150/ 32.2 ) (12^2)
Thus the required value of Ig = 55.90 slug ft^2
Sigma f of x = m(a g)x
which is equal to Sigma f of x = 21.47 ft/s^2 --------- 1
because 200 cos 60 = 150/ 32.2 (ag)x
and Sigma f of y = m a (g)y = 26.45 ft^2 --------2
because 200 sin 60 = 55.90α + 100(6)
The acceleration of the mass centre is a = 7.857 rad / s^2
Thus the magnitude of the acceleration is
aG = 
aG = 34.1 ft/ s^2
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