Answer:
v = 60 m/s
final velocity after 20 seconds depends on how long it continues to accelerate after 20 seconds. Also we do not know the direction to complete the velocity requirements of a scalar value and direction component.
Step-by-step explanation:
If we assume that the acceleration is constant
d = ½at² = ½(Δv/t)t² = ½Δvt = ½(v - 0)t = ½vt
v = 2d/t
v = 2(600)/20 = 60m/s