A bucket crane consists of a uniform boom of mass
M = 201 kg and length L= 59.05 ft that pivots at a point on
the bed of a fixed truck. The truck supports an elevated bucket
with a worker inside at the other end of the boom, as shown in
the figure. The bucket and the worker together can be modeled
as a point mass of weight 201 lb located at the end point of
Suppose that when the boom makes an angle of 68.7° with the
horizontal truck bed, the bucket crane suddenly loses power,
causing the bucket and boom to rotate freely toward the
ground. Find the magnitude of the angular acceleration la of
the system just after the crane loses power. Take the rotation
axis to be at the point where the boom pivots on the truck bed.
Use g = 9.81 m/s2 for the acceleration due to gravity. For unit
conversions, assume that 1 m = 3.28 ft and 1 lb = 4.45 N.
Express your answer to at least two decimal places.