Question

please answer this question ...plss

Answer 1

answer is obviously 3, because as the tray is moving , the water in it experience a pseudo force and because of it the position of water level become unstable with respect to tray in both 1st and second Case so 3rd is the answer

For the answer of ur upper question... is mass is constant everywhere in the universe but it can be change into energy because we know e=mc^2.....