Acar moving at 60 mph will take seconds to come to a complete stop.

It can vary with how effective your brakes and tires are and surface being driven on. But I'd say 1-6 seconds. 

If the water vapor content stays the same and the temperature drops, then the relative humidity increases. its vise versa.if the water vapor content stats the same and the temperature rises, the relative humidity decreases. so, yes, i'd say that temperature and humidity have a strong relationship.