Answer
(a) $29.8m/s$
(b) $4.29s$
Work Step by Step
(a) We can find the ball's initial speed as follows:
$R=\frac{v_{\circ}^2}{g}sin2\theta$
We plug in the known values to obtain:
$90.22=\frac{v_{\circ}^2}{9.81}sin2(45^{\circ})$
$v_{\circ}=29.8m/s$
(b) We know that
$Time \space of \space flight=\frac{2v_{\circ}sin\theta}{g}$
We plug in the known values to obtain:
$Time \space of \space flight=\frac{2(29.8)(sin45^{\circ})}{9.8}=4.29s$
