The object will sink, because it is more dense than water.
Let's see this in detail. There are two forces acting on the object:
- its weight, which points downward, given by
[tex] W=mg=\rho_o V_o g [/tex]
where [tex] \rho_o [/tex] is the object's density, [tex] V_o [/tex] is its volume, and g is the gravitational acceleration.
- The buoyancy force, which points upward, given by
[tex] B=\rho_w V_w g [/tex]
where [tex] \rho_w [/tex] is the water density, [tex] V_w [/tex] is the volume of water displaced by the object.
We see that it is always [tex] W>B [/tex], so the object will sink. In fact:
[tex] \rho_o > \rho_w [/tex]. We are told the object's density is 1.05 g/mL, while the water density is 1.00 g/mL.
[tex] V_o \geq V_w [/tex]: the two volumes are equal when the object is completely submersed, and the volume of water displaced cannot be greater than the volume of the object.
So, W > B, and the object will sink.
