An accelerometer $($body OCA$)$ is installed in a vehicle moving at constant acceleration $a$ at

an angle $$ to the horizontal $($Figure $2).$ The accelerometer's mass is $m=2(1+0\mathrm{.}2)Kg,$

and $C$ is its centre of mass. The torsional spring applies a moment $M_o=10(1-0\mathrm{.}1)Nm,$

to ensure a larger contact force. Find the value of $a$ at which the electric contact will open.

$[$Use $.$