What rules are used when keeping the appropriate distance between two vehicles

You must drive a safe distance behind a vehicle travelling in front of you. Following another vehicle too closely is known as tailgating. If you tailgate you may not be able to safely stop in time to avoid a collision.

You should drive at least 2 seconds behind the vehicle in front during ideal conditions.

Add 1 second extra for each 3m of trailer length—when driving a vehicle towing a trailer or caravan.  

Extra points:  

1. Double your following distance in poor conditions

2. Increase following distances if you're driving a heavy vehicle.

closer examination, however, finds the mcdonald's kind of job highly uneducational in several ways. far from providing opportunities for entrepreneurship (the lemonade stand) or self- discipline, self-supervision, and self-scheduling (the paper route), most teen jobs these days are highly structured — what social scientists call “highly routinized.”  

true, you still have to have the gumption to get yourself over to the hamburger stand, but once you don the prescribed uniform, your task is spelled out in minute detail.  

"facing the rising sun of our new day begun

let us march on till victory is won.",

because the rising sun is a symbol of hope.