The day was extremely hot and ,in no time ,my back up was drenched with __________.

An extremely hot copper wire reacts with steam to give

The hot air rises up as its density increases.

A particle startsits SHM at t=0 . At a particular instant on its way to extreme position , x= (A)/(2) . Find the time taken by the particle to come back to this point after passing through the extreme position. Hint : t_(1) = time taken to go from x=0 to x= (A)/(2) t_(2) = time taken to go to extreme position and come back to mean position = (T)/(2) Required time = (T)/(2) - t_(1)

A particle startsits SHM at t=0 . At a particular instant on its way to extreme position , x= (A)/(2) . Find the time taken by the particle to come back to this point after passing through the extreme position. Hint : t_(1) = time taken to go from x=0 to x= (A)/(2) t_(2) = time taken to go to extreme position and come back to mean position = (T)/(2) Required time = (T)/(2) - t_(1)

A steam boat goes across a lake and comes back (a) On a quit day when the water is still and (b) On a rough day when there is uniform air current so as to help the journey onward and to impede the journey back. If the speed of the launch on both days was same, in which case it will complete the journey in leaser time.