Posted by mike on .
A plastic bobber just barely floats in water. If it weighs 2N in the air, what is its volume

physics 
MathMate,
If the body "barely floats" in water, that means that the density is the same as that of water, equal to 1 kg/l.
The weight, mg = 2N,
its mass, m = 2N/g = 0.204 kg
Therefore the volume is 0.204 kg / (1 kg/l)
= 0.204 l. = 204 cm³