The <em>linear</em> acceleration of collar D when <em>θ = 60°</em> is - 693.867 inches per square second.
<h3>How to determine the angular velocity of a collar</h3>
In this question we have a system formed by three elements, the element AB experiments a <em>pure</em> rotation at <em>constant</em> velocity, the element BD has a <em>general plane</em> motion, which is a combination of rotation and traslation, and the ruff experiments a <em>pure</em> translation.
To determine the <em>linear</em> acceleration of the collar (
), in inches per square second, we need to determine first all <em>linear</em> and <em>angular</em> velocities (
,
), in inches per second and radians per second, respectively, and later all <em>linear</em> and <em>angular</em> accelerations (
,
), the latter in radians per square second.
By definitions of <em>relative</em> velocity and <em>relative</em> acceleration we build the following two systems of <em>linear</em> equations:
<h3>Velocities</h3>
(1)
(2)
<h3>Accelerations</h3>
(3)
(4)
If we know that
,
,
,
,
and
, then the solution of the systems of linear equations are, respectively:
<h3>Velocities</h3>
(1)
(2)
, 
<h3>Accelerations</h3>
(3)
(4)
, 
The <em>linear</em> acceleration of collar D when <em>θ = 60°</em> is - 693.867 inches per square second. 
<h3>Remark</h3>
The statement is incomplete and figure is missing, complete form is introduced below:
<em>Arm AB has a constant angular velocity of 16 radians per second counterclockwise. At the instant when θ = 60°, determine the acceleration of collar D.</em>
To learn more on kinematics, we kindly invite to check this verified question: brainly.com/question/27126557