A small piece of wire 4 cm long is floating on the surface of water. If a force of 560 dnes in excess of its weight is required to pull it up from the surface, find surface tension of water.

A small piece of wire 4 cm long is floating on the surface of water. I

1.	A small piece of wire 4 cm long is floating on the surface of water. If a force of 560 dnes in excess of its weight is required to pull it up from the surface, find surface tension of water.
Answer» SOLUTION :Length of WIRE l=4cm CONTACT length of solid with liquid surface `L=2l =8cm` Surface TENSION `S=F/LimpliesS=560/8=70` DYNE /cm Surface tension of water `=70"dyne"cm^(-1)=0.07Nm^(-1)`