JEE Main | 2014Momentum and CollisionHard
Question
On heating water, bubbles being formed at the bottom of the vessel detatch and rise. Take the bubbles to be spheres of radius R and making a circular contact of radius r with the bottom of the vessel. If r << R, and the surface tension of water is T, value of r just before bubbles detatch is (Density of water is ρw)


Options
A.R2
B.

C.

D.

Solution

When the bubble gets detached,
Buoyant force = force due to surface tension
∫ T × dl sin θ =
π R3 ρwg⇒ T × 2πr ×
π R3 ρwg⇒ r2 =

⇒ r = R2

Create a free account to view solution
View Solution FreeMore Momentum and Collision Questions
A bead can slide a smooth a straight wire and a particle of mass m attached to the bead by a light string of length stri...A closed cylinder of length ′l′ containing a liquid of variable density ρ(x) = ρ0 (1 + αx). F...A wheel has angular acceleration of 3.0 rad/s. In a time of 2 s it has rotated through an angle (in radian)of...An increases in pressure required to decreases the 200 liters volume of a liquid by 0.004% in container is : (Bulk modul...Centre of mass of two uniform rods of same length but made up made of different materials & kept as shown,if the meeting...