- #1

Sabra_a

- 33

- 6

- Homework Statement
- A small air bubble at the bottom of an open 4-m depth water tank

has a radius of 0.5 mm. Due to some reason the bubble comes off

the bottom. Determine the radius of the bubble when it is 0.1 m

below the surface. Assume that the pressure inside the bubble is

2/r above the pressure outside the bubble, where =0.073 N/m –

the surface tension of water-air and r – the radius of the bubble. The

pressure and volume of the air in the bubble are related by the

expression pV=const.

- Relevant Equations
- ρ=2 σ/r

P=ρgh+P

**Homework Statement:**A small air bubble at the bottom of an open 4-m depth water tank

has a radius of 0.5 mm. Due to some reason the bubble comes off

the bottom. Determine the radius of the bubble when it is 0.1 m

below the surface. Assume that the pressure inside the bubble is

2/r above the pressure outside the bubble, where =0.073 N/m –

the surface tension of water-air and r – the radius of the bubble. The

pressure and volume of the air in the bubble are related by the

expression pV=const.

**Homework Equations:**ρ=2 σ/r

P=ρgh+P

I calculated the pressure inside the bubble multiplying 2 into the given surface tension and the reduce I'm not sure if I should convert the mm to m for the radius or its not required.

ρ=2 σ/r

ρ=2 0.073/0.5

ρ= 0.292

the substituted that in P=ρgh+P

= (0.292)(9.81)(4) + 101300

=101311.4

this is what I did so far