Question

Problem 8:

A vertically downward force of magnitude 10 N is required to immerse a homogeneous object of weight 40 N completely in water. What is the density of the object?

Answer 1

$\rho_w g\frac m\rho =P+F,$

$\frac {\rho _w}{\rho}P=P+F,$

$\frac{\rho_w}{\rho}=\frac{P+F}P,$

$\rho=\rho_w\frac P{P+F},$

$\rho=800~\frac {kg}{m^3}.$