5.20 .. Apparent Weight. A 550-N physics student stands on a
bathroom scale in an 850-kg (including the student) elevator that is
supported by a cable. As the elevator starts moving, the scale reads
450 N. (a) Find the acceleration of the elevator (magnitude and
direction). (b) What is the acceleration if the scale reads 670 N?
(c) If the scale reads zero, should the student worry? Explain.
(d) What is the tension in the cable in parts (a) and (c)?