we crawled a long through the city traffic at 6m/s for 5m'. than we left the city & we gradually acceleration to 24m/s2 in 20s

Answer 1

What is your question?
V = Vo + a*T = 6 + 24*20 = 486 m/s.

d = Vo*T + 0.5a*T^2 = 6*300 + 0.5*24*20^2 = __meters.