A popular brand of doughnut is made in an assembly-line fashion. First, the white, uncooked doughnut is dropped into hot vegetable oil ( ρ= 949 kg/m3) where it browns on one side as it cooks. It is then flipped over and browned on the other side. The final product still has a white stripe around the middle where the dough always stays out of the oil, as indicated in the figure .
Assuming the doughnut has a cylindrical shape of height H and diameter D, and that the height of the white stripe is 0.25H, find the density of the doughnut.
Fbuoyant=weight of doughnut
The Attempt at a Solution
I have not idea where to start.. the only conclusion I have come to is that the doughnut it floating so it's density has to be less than oil.
I know i must use most of these equations but I'm confused on which ones to use, considering i don't have numbers to plug in.
The whole white line in the center is throwing me off...