You can determine the object's velocity according to the time it has accelerated by the equation:
v = at
where
v is the velocity of the object.
a is the acceleration, In this case 2g (Thrust 2) or 19,6 m/s² or 64 ft/s² .
t is the measure time in seconds you have to accelerate
at is the product of a times t
Now... first off: 75kph = 20,83 m/s once the ship reaches this velocity it is safe... unless the cloud has already reached it by then... so that is the target to meet or beat.
So how manny second did you have to accelerate again? Does it really say?
Never mind; lets calculate how many seconds you "need":
20,83 m/s = 19,6 m/s² * t
20,83 m/s / 19,6m/s² = 1,06 seconds
So as long as you have at least 1,06 seconds to accelerate you will not get caught by that cloud... during this second you also get to do at least three pilot checks... (really fast ones)...
I'd say it is all disregarded in favor of dramatic tension and good, epic action. Screw science! I want good drama!
But never the less... I think I'll keep the cloud speed to myself and only tell the players that they are in trouble...
(My math is a little rusty so I could be wrong, I'm sure there are math-buffs out there who will prove me wrong somehow.)
/wolf