B. 54.4 m/s
Explanation:
Using the equation;
S = ut + 1/2at²
Where;
v is the final velocity
u is the initial velocity,
a is the acceleration,
s is the displacement
Therefore;
975 =(7.55×31.5) + (0.5×a× 31.5²)
975 = 237.825 + 496.125a
496.125a = 737.175
a = 1.486 m/s²
But;
v = u + at
= 7.55 m/s + (1.486 × 31.5)
= 54.355 m/s
= 54.4 m/s
Therefore;
The final velocity is 54.4 m/s