JEE Main · 2019 · 10 Apr 2019 · Shift 2 · Fluid Mechanics

A cubical block of side 0.5 m floats on water with

30%

of its volume under water. What is the maximum weight that can be put on the block without fully submerging it under water?
[Take density of water

= 1 0^{3} kg / m^{3}

]

(A)46.3 kg
(B)65.4 kg
(C)30.1 kg
(D)87.5 kg✓ Correct

Answer: (D)

Solution

Floating with

30%

submerged tells us the block's density, since the displaced water supports its weight:

ρ_{block} = 0.30 \times 1000 = 300 kg m^{- 3}

. Fully submerged the block displaces its whole volume

V = (0.5)^{3} = 0.125 m^{3}

, and the extra load it can then carry is the difference in buoyancy,

M = V (ρ_{w} - ρ_{block}) = 0.125 \times (1000 - 300) = 87.5 kg

JEE Main · 2019 · 10 Apr 2019 · Shift 2 · Single correct option

Practise more: all JEE Main PYQs on Fluid Mechanics →

More JEE Main questions on Fluid Mechanics

Given below are two statements:
Statement I: Pressure of fluid is exerted only on a solid surface in contact as the fluid-pressure does not exist everywhere in a still fluid.
Statement II: Excess potential energy of the molecules on the surface of a liquid, when compared to inter …
JEE Main 2026View solution →
When a part of a straight capillary tube is placed vertically in a liquid, the liquid raises upto certain height h. If the inner radius of the capillary tube, density of the liquid and surface tension of the liquid decrease by $1%$ each, then the height of the liquid in the tube …
JEE Main 2026View solution →
Surface tension of two liquids (having same densities), $T_{1}$ and $T_{2}$ , are measured using capillary rise method utilizing two tubes with inner radii of $r_{1}$ and $r_{2}$ where $r_{1} > r_{2}$ . The measured liquid heights in these tubes are …
JEE Main 2026View solution →
The terminal velocity of a metallic ball of radius 6 mm in a viscous fluid is $20 cm / s$ . The terminal velocity of another ball of same material and having radius 3 mm in the same fluid will be
____ $cm / s$ .
JEE Main 2026View solution →
A small metallic sphere of diameter 2 mm and density $10.5$ g/cm³ is dropped in glycerine having viscosity 10 Poise and density $1.5$ g/cm³ respectively. The terminal velocity attained by the sphere is $____$ cm/s.
( $π = \frac{22}{7}$ and $g = 10$ m/s²)
JEE Main 2026View solution →
Sixty four rain drops of radius 1 mm each falling down with a terminal velocity of $10 cm / s$ coalesce to form a bigger drop. The terminal velocity of bigger drop is ______ $cm / s$ .
JEE Main 2026View solution →