Mechanical Properties of Fluids

A submarine is designed to withstand an absolute pressure of 100 atm. How deep can it go below the water surface?

(Consider the density of water = 1000 kg m^–3, 1 atm = 1 × 10⁵ Pa and gravitational acceleration g = 10 m/s²)

The venturi-meter works on:

A raindrop with radius \(\mathrm{R}=0.2 \mathrm{~mm}\) falls from a cloud at a height \(h=2000 \mathrm{~m}\) above the ground. Assume that the drop is spherical through its fall and the force of buoyance may be neglected, then the terminal speed attained by the raindrop is :

[Density of water \(f_{\mathrm{w}}=1000 \mathrm{kg m}^{-3}\) and Density of air \(f_{\mathrm{a}}=1.2 \mathrm{~kg}^{-3}, g=10 \mathrm{~m} / \mathrm{s}^{2}\), Coefficient of viscosity of air \(\left.=1.8 \times 10^{-5} \mathrm{Nsm}^{-2}\right]\)

An air bubble of volume \(1 \mathrm{~cm}^{3}\) rises from the bottom of a lake \(40 \mathrm{~m}\) deep to the surface at a temperature of \(12^{\circ} \mathrm{C}\). The atmospheric pressure is \(1 \times 10^{5} \mathrm{~Pa}\), the density of water is \(1000 \mathrm{~kg} / \mathrm{m}^{3}\) and \(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2}\). There is no difference of the temperature of water at the depth of \(40 \mathrm{~m}\) and on the surface. The volume of air bubble when it reaches the surface will be

[JEE Main 2023, 8 Apr (Shift 1)]

A fully loaded aircraft has a mass of \(5.4 \times 10^{5} \mathrm{~kg}\). Its total wing area is \(500 \mathrm{~m}^{2}\). It is in level flight with a speed of \(1080 \mathrm{~km} / \mathrm{h}\). If the density of air is \(1.2 \mathrm{~kg} \mathrm{~m}^{-3}\), the fractional increase in the speed of the air on the upper surface of the wings relative to the lower surface in percentage will be \(\left(g=10 \mathrm{~m} / \mathrm{s}^{2}\right)\)

A capillary tube of radius \( r \) is immersed in water and water rises in it to a height \( h \). The mass of the water in the capillary is \( 5 \mathrm{~g} \). Another capillary tube of radius \( 2 r \) is immersed in water. The mass of water that will rise in this tube is:

[NEET 2020]

The velocity of a small ball of mass \( M \) and density \( d \), when dropped in a container filled with glycerine becomes constant after some time. If the density of glycerine is \( \frac{d}{2} \), then the viscous force acting on the ball will be:

[NEET 2021]

A liquid does not wet the solid surface if angle of contact is

A barometer is constructed using a liquid(density\(=760\mathrm{kg}/{\mathrm{m}}^{3}\)). What would be the height of the liquid column, when a mercury barometer reads \(76\mathrm{cm}\)? (density of mercury \(=13600\mathrm{kg}/{\mathrm{m}}^{3}\))

[Re-NEET 2020]

The amount of energy required to form a soap bubble of radius \(2\mathrm{cm}\) from a soap solution is nearly: (surface tension of soap solution \(=0.03\mathrm{N}{\mathrm{m}}^{-1}\) )

[NEET 2023]