# Need help with homework problem - Archimede's principle

by PHYclueless
Tags: archimede, homework, principle
 HW Helper P: 1,449 The ferryboat experiences an additional upwards boyancy force, $B$, equal to the weight of the water it displaced as it sank deeper into the water when the truck pulled up onto it. This force is given by $$B=mg$$ where $m$ is the mass of the displaced water (by the ferryboat). We can use the density of water to calculate the mass of the displaced water: $$\rho = \frac{m}{V}$$ where $V$ is the volume of the displaced water - the volume of the ferry that sank into the water as the truck drove onto it. The mass is therefore given by $$m=\rho V$$ changing the original formula to $$B=\rho Vg$$