A steel needle sinks in water but a steel ship floats. Explain, how?

cbse
floatation

#1

(i) A steel needle sinks in water but a steel ship floats. Explain, how?
(ii) Why do you prefer a broad and thick handle of your suitcase ?


#2

(i) Ship displaces more water than needle as volume of ship is more than that of needle. Since, upthrust depend on volume of object (U = Vdg), so more the volume of object, more upthrust act on it and object floats.
(ii) Since, pressure act on the body is inversely proportional to the surface area of contact, i.e.
It means that more the area of contact, less pressure will act on the body. As the broad and the thick handle of our suitcase has large area, due to which less pressure acts on our hand and it is very easy to take from one place to another.