Two soap bubbles of radii 3 cm and 4 cm are present in vacuum. They are made from the same soap solution and combine isothermally without gas loss. If the radius of the final bubble is N cm, find N.
Physics · Properties of solid and fluid · properties of fluid and surface tension
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Question

Two soap bubbles of radii 3 cm and 4 cm are present in vacuum. They are made from the same soap solution and combine isothermally without gas loss. If the radius of the final bubble is N cm, find N.

G1 Physics · Accepted Answer

For isothermal combination of soap bubbles in vacuum, R(final)² = R₁²+R₂². Therefore, R(final)² = 3²+4² = 9+16 = 25. Hence, R(final) = 5 cm. Thus, N = 5.