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A spherical soap bubble of radius 3 cm is formed inside another spherical soap bubble of radius 6 cm. If the internal pressure of the smaller bubble of radius 3 cm in the above system is equal to the internal pressure of the another single soap bubble of radius r cm. The value of r is ____
- 2.00
- 2
- 4.00
- 6.00
Correct answer: 2.00
Solution
The internal pressure of a soap bubble is inversely proportional to its radius, according to the formula P = 4T/r, where T is the surface tension. Since the internal pressure of the smaller bubble (radius 3 cm) equals that of another bubble with radius r, we can set up the equation 4T/3 = 4T/r, leading to r = 2 cm.
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