Sawing a board in half is a physical change not a chemical change the board doesnt change wood or whatever material it is is still would still be wood
If it were burned it would be a chemical change but its properties stay the same atomically so thats why its not a chemical change.
sorry what us this i don't get it
Well, you could get the mass as

ad then

, where

is the sea level weight,

the sea level accel.,

the accel. above while

the weight above.