The character 速su4 is often used together with 度 du4, so it'll make the phrase, 速度 which means speed.
早 means morning/early.
So actually I don't see a similarity between them.
Numerically, the difference between 8 and 14 is 6 units.
In terms of age, a lot can be different. Height and weight, for example, are key. A 14-year-old will generally be taller and heavier than an...