[填空题]
A person stands on a bathroom sca .ir5hi1h)n8 0yssf 2 e/kzgklle inx8x( 90a4oqdk1/sjt 1ne uwvn a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.75 of the person’s regular weight. Calculate the acceleration of the elevator, and find the direction of acceleration. 1 9 e4 1 n(dn0u8txkjxos/awvq