Need with 2 nuclear power plant questions:

1. for what purpose does the water systems within a reactor core form a closed loop?

2. how is a nuclear power plant similar to a coal fired power plant?

Ais not a compound machine. a. bolt b. shovel c. handcart (dolly) d. see-saw (teeter totter)

(**i would really appreciate if this was answered soon** ) which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

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)