If b is the trait for brown eyes and b is the trait for blue, and a homozygous dominant dad and a homozygous recessive mom have off-spring. how many of the f1 generation will be bb?

Zero of the offspring will be bb.  Since each offspring receives one allele from each parent, all will receive a B from Dad and a b from Mom, making all of the offspring heterozygous (Bb) and brown-eyed.

the farther away the object is from the central star (the sun) it's gravitainal pull on the object is weaker when it is farther

explanation:

geologic time scale (for gradpoint) =)