Archimedes Principle - Example 5

Example 5
The density and mass of a metal block are 5.0×10³ kg m^-3 and 4.0kg respectively. Find the upthrust that act on the metal block when it is fully immerse in water.
[ Density of water = 1000 kgm^-3 ]

Answer:
In order to find the upthrust, we need to find the volume of the water displaced. Since the block is fully immersed in water, hence the volume of the water displaced = volume of the block.

Volume of the block,
$$V=\frac{m}{\rho }=\frac{4}{5.0\times {10}^3}=0.0008m^3$$
Upthrust acted on the block,
$$\begin{array}{l}F=\rho Vg\\ F=(1000)(0.0008)(10)=8N\end{array}$$