The work done in increasing the volume of a soap bubble of radius r to...
Introduction
To calculate the work done in increasing the volume of a soap bubble, we need to consider the surface tension of the soap solution and the change in radius of the bubble. In this case, we are given the initial radius of the bubble, and we need to find the work done when the volume is increased to 27 times the initial volume.
Formula for Surface Tension
The formula for surface tension is given by:
T = (P * r) / 2Where T is the surface tension, P is the pressure inside the bubble, and r is the radius of the bubble.
Change in Volume
The volume of a sphere is given by the formula:
V = (4/3) * π * r^3If we increase the volume by a factor of n, the new volume will be:
V' = n * VSo, in this case, the new volume is:
V' = 27 * VChange in Radius
We can calculate the change in radius using the formula for volume:
V = (4/3) * π * r^3Solving for r, we get:
r = (3V / 4π)^(1/3)So, the initial radius is:
r = (3V / 4π)^(1/3)And the final radius, when the volume is increased to 27 times, is:
r' = (3V' / 4π)^(1/3)Substituting the value of V' from earlier, we get:
r' = (3 * 27V / 4π)^(1/3)Simplifying further, we get:
r' = 3^(1/3) * rWork Done
The work done in increasing the volume of the soap bubble can be calculated using the formula:
W = T * ΔAWhere W is the work done, T is the surface tension, and ΔA is the change in surface area.
The initial surface area of the bubble is given by:
A = 4π * r^2And the final surface area, when the volume is increased to 27 times, is given by:
A' = 4π * r'^2Substituting the value of r' from earlier, we get:
A' = 4π * (3^(1/3) * r)^2Simplifying further, we get:
A' = 36π * r^2The change in surface area is then:
ΔA = A' - A = 36π * r^2 - 4π * r^2 = 32π * r^2Finally, substituting the values of T and ΔA into the formula for work done, we get:
W = T * ΔA = (P * r / 2) * (32π * r^2)Simplifying further, we get:
W = 16π * P *