Question

Please answer to this question.
If the diameter of a soap bubble is 10mm and it's surface tension is 0.04 N/m, find the excess pressure inside the bubble.

Answer 1

Diameter is 10mm thus radius is 5mm i.e.5×10^-3 m.
Excess presssure for soap bubble is given by dP=4×surface tension divided by radius
So,dP=4×0.04÷5×10^-3

therefore dP=32 N/m^2.
Hope this helps☺

Answer 2

Answer: 32 N/m²

Explanation:

Inside a soap bubble, excess pressure is given by:

ΔP = 4S/R

Where, S is the surface tension and R is the radius of the bubble.

It is given that: S = 0.04 N/m

Diameter of the bubble, d = 10 mm = 0.010 m

Radius of the bubble, R = d/2 = 0.005 m

Thus, ΔP = (4 × 0.04 N/m) / 0.005 m = 32 N/m²