337I think yes.
An iron nail is placed on water. It sinks as the normal reaction is not enough to keep it floating. So work by normal force = fs cos theta. But here the nail sinks, so work by normal reaction is opposite to that of the direction of displacement. So theta =180. And cos 180=-1. So work done is negative, but some work is done.
Hope it helps....
Debal Roy we can explain the example you given above with archimedes priciple...it would be better if you will explain my question with solid surface...think again...but your try is good....Upvote·0· Reply ·2013-03-13 21:34:16
