A glass flask weighing 390 g having internal volume 500 cc just floats when half of it is filled with water. Specific gravity of the glass is
Options
(a) 2.8
(b) 1.8
(c) 1
(d) 2.5
Correct Answer:
2.8
Explanation:
Weight of the flask + 250 c.c. of water is balanced by V₂ gm of water.
Where V₂ is the external volume.
.·. (390 + 250)g = V₂ × 1 × g ⇒ V₂ = 640 c.c.
.·. Volume of the material = (640 – 500) c.c. = 140 c.c.
.·. Density of glass = 390 g / 140 c.c. = 2.8 g/c.c.
i.e. Specific gravity = 2.8