Question

An aluminium alloy (density 2600 kg/$m^3$) casting is to be produced. A cylindrical hole of 100 mm diameter and 100 mm length is made in the casting using sand core (density 1600 kg/$m^3$) . The net buoyancy force (in Newton) acting on the core is_____

• A. 7.7

Answer 1

The correct option is A 7.7
Volume of core=$\frac{\pi }{4}{D}^{2}H=0.785\times {0.1}^2\times 0.1$
$=7.85\times {10}^{-4}{m}^3$

Net buoyancy force=$({\rho }_{Al}-{\rho }_{core})V_{core}g$
=$1000\times 9.81\times 7.85\times {10}^{-4}$
=7.7 N