My sister needs help on this

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?

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)