A spherical soap bubble has a radius r and a surface tension γ and contains air at a pressure p. More air is blown into the bubble, causing the radius to increase to 2r.

(a) The surface tension in this now inflated soap bubble is

(A) slightly less than γ. (B) equal to γ.

(C) slightly more than γ. (D) 2 γ.

(b) The pressure of the air inside this now inflated soap bubble is

(a) slightly less than (b) equal to p.

(c) slightly more than p. (d) 2p.

When air is blown into a soap bubble, causing its radius to double, the new surface tension of the bubble compared to the original surface tension γ will actually be slightly less than γ. This is because as the bubble expands, the original surface tension is spread out over a larger surface area, resulting in a decrease in the surface tension per unit area.

On the other hand, the pressure of the air inside the now inflated soap bubble will be equal to the original pressure p. This is because the pressure inside the bubble is determined by the balance between the internal pressure pushing outwards and the surface tension acting inwards, and this balance remains the same regardless of the bubble's size.

So, in summary, the surface tension of the inflated soap bubble will be slightly less than the original γ, while the pressure inside the bubble will remain equal to the original pressure p.