Q. What would be the gauge pressure inside an air bubble of 0.2mm radius situated just below the surface of water ? (Surface Tension of water = 0.07 N/m)
Pi-Po = 4T / r
Where Pi= The pressure inside the bubble
Po= The pressure outside the bubble = Here when er talk about the surface the pressure can be considered to be zero
T = surface tension , r = radius of the bubble= 0.2 mm = 0.2/1000 m
on substituing the values = P = 4 x 0.07 x1000 / 0.2 = 1400 N
Where Pi= The pressure inside the bubble
Po= The pressure outside the bubble = Here when er talk about the surface the pressure can be considered to be zero
T = surface tension , r = radius of the bubble= 0.2 mm = 0.2/1000 m
on substituing the values = P = 4 x 0.07 x1000 / 0.2 = 1400 N