Answer
a). $0.967s$
b). $4.19m$
c). $12.7m/s$
Work Step by Step
a). $v_{y}=v_{0}sin\theta=5\times0.5=2.5m/s$
$H=v_{y}t+\frac{1}{2}gt^{2}$
H=7m,
From above equation, $t=0.967s$
b). $x=(vcos\theta) t=5cos30^{\circ} \times 0.967=4.19m$
c). Vertical component = $v_{y}t+gt=2.5\times 0.967+9.8\times0.967=11.9m/s$
Thus, impact speed =$ \sqrt (4.33^{2}+11.9^{2})=12.7m/s$
