Answer:
The diameter is twice that, or approx. 7.90 units.
Step-by-step explanation:
the equation for the volume of a cylinder of radius r and height h is
V = πr²h.  Here we need to calculate the diameter after having found the radius.  Solving V = πr²h for r², we get:
            V
r² = -----------
          πh
Substituting the given values, we obtain for r² the following:
          145 units³
r² = ------------------------  = 15.6 units²
        3.14159(5 units)
Taking the square root of both sides, we get:
r = √15.60, or approx. 3.95 units.
The diameter is twice that, or approx. 7.90 units.