A simple compass can be made by placing a small bar magnet on a cork floating in water. $($The bar magnet is made of iron.$)$

$($a$)$

What fraction of a plain cork will be submerged when floating in water?

$($b$)$

If the cork has a mass of $12\mathrm{.}0$ g and a $25\mathrm{.}0$ g magnet is placed on it$,$ what fraction of the cork will be submerged?

$($c$)$

Will the bar magnet and cork float in ethyl alcohol?

YesNo$$