A certain system is described by the model 9x + cx + 4x = us(t) Set the

Question:

A certain system is described by the model
9ẍ + cẋ + 4x = us(t)
Set the value of the damping constant c so that both of the following specifications are satisfied. Give priority to the overshoot specification. If both cannot be satisfied, state the reason. Time is measured in seconds.
1. Maximum percent overshoot should be as small as possible as and no greater than 20%.
2. 100% rise time should be as small as possible and no greater than 3 s.