Answer
a). $-8.25m/s^{2}$
b). $0.841$
c). $31m/s$
Work Step by Step
a). $a=\frac{v^{2}-u^{2}}{2S}=\frac{-29.15^{2}}{2\times51.5}=-8.25m/s^{2}$
b). Coefficient of friction $=-\frac{a}{g}=0.841$
c). initial velocity = $\sqrt (v^{2}-2aS)=\sqrt (0^{2}-2\times(-8.25)\times57.3)=31m/s$