A person stands on a bathroom scale in a motionless elevator. When the elevator begins to move, the scale briefly reads only 0.67 of his/her regular weight. Calculate the acceleration of the elevator and find the direction of acceleration. (Choose upward as the positive y-direction and express the direction of the acceleration using the sign of the result, which must be in units of m/s? and include 2 digit after the decimal point. Maximum of 5% of error is accepted in your answer. Take g=9.80 m/s?.)