Answer:
a)
[tex]{ \tt{s = ut + \frac{1}{2} {at}^{2} }} \\ \\ { \tt{s = (7 \times 15) + \frac{1}{2} \times 2.5 \times {15}^{2} }} \\ \\ { \tt{s = 105 + 281.25}} \\ { \tt{s = 386.25 \: m}}[/tex]
b)
[tex]{ \tt{v {}^{2} = {u}^{2} + 2as}} \\{ \tt{ {v}^{2} = {7}^{2} + (2 \times 2.5 \times 386.25)}} \\ { \tt{ {v}^{2} = 1980.25}} \\ { \tt{v = 44.5 \: m}}[/tex]
