Question

D
of Submarine is at depth of 512 meter below sea level

Answer 1

eight above sea levels are considered as + ve

and height / Depth below sea level is taken as - ve

So a submarine at a depth of 512 m

= - 512  m  

You can consider it like a  XY  plane

where Y above 0 is + ve and below 0 is - ve

Sea level is considered Zero  

-512 m

Learn more:

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pls mark brainiest