To find the time when the volleyball reaches its maximum height, we can use the vertex formula for a quadratic equation of the form \( h(t) = at^2 + bt + c \). The time \( t \) at which the maximum height occurs is given by:
\[ t = -\frac{b}{2a} \]
In this case, the equation is:
\[ h(t) = -16t^2 + 33t + 6 \]
Here, \( a = -16 \) and \( b = 33 \). Plugging in these values:
\[ t = -\frac{33}{2 \cdot -16} = \frac{33}{32} \approx 1.03125 \]
This rounds to approximately 1.03 seconds.
So the domain of the ball when it reaches its maximum height is 1.03 seconds.