Lungs r covered by double layered pleura with pleural fluid filled between them . It reduces friction on the lungs .

rn

Xplain the statement .

 Yes true 

If anything is rubbed on a solid surface it faces more friction comparatively when it is rubbed against a liquid because of more no. of particles provide friction in case of solid

Another example of this --

We can move our hands easily in air as it faces less friction but if we move it in water then we need to apply more force (There is one  another reason for this that molecules of air are loosely bound as compared to water)

Thanks