A soap bubble has a diameter of 4mm. Cakculate the pressure inside it if the atmospheric pressure outside is 10^5Nm^2. The surface tension of soap = 2.8 * 10^-2N/m

The formula for determining the pressure inside a soap bubble is expressed as

Pi - Po = 4T/r

Where

Pi represents the pressure inside the bubble.

Po represents the pressure outside the bubble or the atmospheric pressure.

T represents the surface tension.

r represents radius of the bubble.

From the information given,

Diameter of bubble = 4mm. Converting to meters, it becomes

4/1000 = 0.004m

Radius of bubble = 0.004/2 = 0.002m

T = 2.8 * 10^-2N/m

Po = 1 * 10^5Nm^-2

Therefore,

Pi - 10^5 = 4 * 2.8 * 10^ - 2/0.004

Pi - 10^5 = 28

Pi = 28 + 1 * 10^5 = 100028Nm^-2

Look it up it will give the right anwser