[填空题]
A person stands on a b7*hxkiti4 hq3athroom scale in a motionless elevator.; m:5avt hcopx,zp7mfq8o8 m8ihb 9z- When the elevator begins to move, the scale briefly reads only 0.75 of the p8 ;mqxi,8mhfpo 8a9:c7v5pomhzz-bt erson’s regular weight. Calculate the acceleration of the elevator, and find the direction of acceleration.
