A solid object has volume 2.0×10−3m3 and density 980kgm−3. It just floats in river water at 25∘C whose density is 997kgm−3. The river water is then heated uniformly to 70∘C, at which temperature its density becomes 978kgm−3.
(i) State the condition that determines whether an object floats or sinks in a fluid.
(ii) Determine whether the object will float or sink in the heated water. Give calculations to support your answer.
(iii) If the object becomes fully submerged in the heated water, calculate its apparent weight in that water.