A man is walking on a plank which is placed horizontally across two surpports so that equal lengthbis project at each end, if the plank is 5m long and has a mass of 3okg, what is the greatest distance from each end eat which the surpports can be placed so that a man of mass song can stand anywhere on the plank without im falling off the supports.

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)