Required information

Problem $15\mathrm{.}132-$ Relative velocity and acceleration

The instant shown, bar $\backslash ($ A B $\backslash )$ has a constant angular velocity of $\backslash (5\mathrm{.}500\backslash$mathrm$\{$rad$\}/\backslash$mathrm$\{$s$\}\backslash )$ clockwise.

Problem $15\mathrm{.}132.$b $-$ The angular acceleration of bar DE

Determine the angular acceleration of bar $\backslash ($ D E $\backslash ).($Round the final answer to three decimal places.$)$