Think and Win!!?

Question

2 Balls of the same metal. volume each one (0.0002 m3). one Impermeable and the other oner rivet . when they were placed in water (density 1000 kg / m 3 ) we found that one sank and the other attached. Find The size of the vacuum created in the ball rivet. note that the density of the metal ( 2707 kg / m 3) (G= 9.8 m / s 2) .

Answer 1

Poorly described. Attached to what? What's a ball rivet?