Tomas wants to paint his bedroom. He goes to the store and buys two cans of paint. Which simple machine would make it easier for him to open the cans?
A a lever
B. a pulley
C. an inclined plane
D. a wheel and axle

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)