What force is required to completely immerse a 2 g plug in water? the density of the plug is 0.2g / cm3?

The plug will be acted upon by the force of Archimedes Fa and the force of gravity P in opposite directions:
Fa = r * g * V, where r is the density of water, g is the acceleration of gravity, V is the volume of the plug.
Find the volume of the plug: V = m / r1 (r1 is the density of the plug).
Fa = (r * g * m) / r1
r1 = 0.2 g / cm ^ 3 = 200 kg / m ^ 3;
Fa = (1000 kg / m ^ 3 * 10 m / s ^ 2 * 0.002 kg) / (200 kg / m ^ 3) = 0.1 N.
The force of gravity will be equal to P = mg = 0.002 kg * 10 m / s ^ 2 = 0.02 N.
The resultant is directed upwards (pushing prevails):
R = Fa – P = 0.1 N – 0.02 N = 0.08 N.
For the cork to sink, you need to apply a force of 0.08 N.
Answer: 0.08 N.