Surface Tension Formulas
Searching for a One-Stop Destination where you can find the Surface Tension Formulas? If so, you have come the right way and we have listed the Surface Tension Formula Sheet that makes your job simple. Make the most out of Surface Tension Formulas and overcome the struggle of searching everywhere. The Formula List includes the topics like Shape of Meniscus, Surface Energy Density, Rise or Fall of Liquid in Capillary, etc. Avail the Physics Formulas present to get help on any random topic of Physics.
Formulas List for Surface Tension
1. Surface tension
The free surface of a liquid behaves as stretched membrane. The force per unit length in a perpendicular direction on an imaginary line drawn in the surface of a liquid is called surface tension is also equal to the work done to increase the surface area of a liquid by unity.
T = \(\frac{F}{\ell}=\frac{\Delta W}{\Delta A}\) N/m or J/m2
2. Surface energy density
E = \(\frac{\Delta \mathrm{W}}{\Delta \mathrm{A}}\) = T
3. Shape of meniscus
- Fa = \(\frac{F_{c}}{\sqrt{2}}\) ; Plane, ╬╕ = 90┬░ No change
- Fa < \(\frac{F_{c}}{\sqrt{2}}\) ; Convex, ╬╕ > 90┬░ Leave fall
- Fa > \(\frac{F_{c}}{\sqrt{2}}\) ; Concave, ╬╕ < 90┬░ Level rise
4. Rise or fall of liquid in a capillary
h = \(\frac{2 \mathrm{T} \cos \theta}{\mathrm{rdg}}\)
If capillary is inclined by an angle Φ with vertical, h is constant but length of liquid column
l = \(\frac{\mathrm{h}}{\cos \phi}\)
h ∝ \(\frac{1}{r}\)
or h1r1 = h2r2 (JurinΓÇÖs law)
If radius of capillary is r and radius of curvature of meniscus is R then-
r = R cos ╬╕
5. Excess pressure due to surface tension
In a drop p = \(\frac{2 \mathrm{T}}{\mathrm{r}}\)
In a bubble in air p = \(\frac{4 \mathrm{T}}{\mathrm{r}}\)
In an air bubble in liquid
p = \(\frac{2 \mathrm{T}}{\mathrm{r}}\)
If surface is curved in two directions,
P = T\(\left(\frac{1}{r_{1}}+\frac{1}{r_{2}}\right)\)
6. Radius of curvature of common surface of two bubbles in contact
r = \(\frac{r_{1} r_{2}}{r_{2}-r_{1}}\)
7. Radius of bubble formed when two bullbes coalesce
r = \(\sqrt{r_{1}^{2}+r_{2}^{2}}\)
8. Work done in blowing a bubble
W = 8πT(r12 + r22)
9. Breaking of a big drop in n droplets
n = \(\frac{\mathrm{R}^{3}}{\mathrm{r}^{3}}\)
Increase in area ╬öA = 4╧Ç(nr2 – R2), W =4╧ÇTR3\(\left(\frac{1}{r}-\frac{1}{R}\right)\)
Fall in temperature Δθ = \(\frac{3 \mathrm{T}}{\mathrm{Jsd}}\left(\frac{1}{\mathrm{r}}-\frac{1}{\mathrm{R}}\right)\)
10. Liquid film between parallel plates
Required to separate the plates.
F = \(\frac{2 \mathrm{AT}}{\mathrm{t}}\)
Explore more related concepts or any other topic of Physics from a go-to place for Formulas i.e.  Physicscalc.Com and clarify all your concerns.
