The controlling force in a spring controlled governor is $1500$ N when the radius of rotation of the balls is $200$ mm

and $887\mathrm{.}5$ N when it is $130$ mm $.$ The mass of each ball is $8$ kg $.$ If the controlling force curve is a straight line,

determine the controlling force and the speed of rotation when the radius of rotation is $150$ mm $.$ Also find the

increase in the initial tension so that the governor is isochronous. What will be the isochronous speed?