Given:
m = 70 kg, mass
F = 650 N, force
t = 0.8 s, time
Calculate the acceleration.
a = F/m = (650 N)/(70 kg)
= 9.2857 m/s²
Because the initial velocity is zero, the final velocity (after time 0.8 s) is
v = a*t = (9.2857 m/s²)*(0.8 s)
= 7.43 m/s
Answer: 7.43 m/s (nearest hundredth)