Hi there!
Assuming the track is frictionless:

Cancel out the masses and rearrange to solve for velocity:

Plug in the given height and let g = 9.8 m/s²:

It means every thing is made out of Atoms and some things are element componds so elements are the "backbone" of the compounds.
Well,
For the first one, the answer would be C, because all organisms in Kingdom Animalia must eat in order to survive.
For the second one, all of the options are in Kingdom Animalia, but worms (A) and clams (C) are invertebrates. So that leaves options B and D.
Answer:
4. F
5. F
Explanation:
jupiter constantly has hurricanes and uranus has storms often too.
lightning can move many ways including from cloud to cloud and even from ground ton sky (seriously look it up it's cool)