Answer is: ending velocity at the finish line was 20,75 m/s.
v(initial velocity) = 5 m/s.
a = 9 m/s²; acceleration attained by the body.
t = 1,75 s; sprinting time.
Ending velocity is defined as the velocity attained by a body after completing distance at certain time interval:
v(ending velocity) = v(initial velocity) + a·t.
v(ending velocity) = 5 m/s + 9 m/s² · 1,75 s.
v(ending velocity) = 20,75 m/s.