Question
Physics Question on potential energy
The potential energy possessed by a soap bubble, having surface tension equal to 0.04N/m of diameter 1cm is
A
6π×10−6J
B
2π×10−6J
C
8π×10−6J
D
4π×10−6J
Answer
8π×10−6J
Explanation
Solution
Given: Surface tension in soap bubble (T) =0.04N/m and diameter of soap bubble (d)=1cm =0.01m or radius (r)=0.005m. We know that potential energy = Surface tension × Surface area. We also know that for a soap bubble, there are two surfaces. Therefore total area =2×4πr2. Thus potential energy =(0.04)×[2×4π×(0.005)2]=8π×10−6J.