After a supernova explosion the core may become a ?

If steel is more dense that lake water, why can a boat float

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

Auniform brick of length 25 m is placed overthe edge of a horizontal surface with a maximum overhang of 12.5 m attained withouttipping. now two identical uniform bricks of length25 m are stacked over the edge of a horizontalsurface. what maximum overhang is possible forthe two bricks (without tipping)? answer in units of m.