#### Answer

$a). 4.24^{\circ}$
$b). 44.56s$

#### Work Step by Step

a). $tan^{-1}(\frac{6.75}{0.5})=85.76^{\circ}$
Reqd. angle=$90^{\circ}-85.76^{\circ}=4.24^{\circ}$
b). $cos4.24^{\circ}\times 6.75m/s=6.732m/s$
Time taken $=\frac{300m}{6.732m/s}=44.56s$