Spring scales work by measuring the displacement of a spring that supports both the platfo...

Spring scales work by measuring the displacement of a spring that supports both the platform and the object, of mass m, whose weight is being measured. Neglect the mass of the platform on which the mass sits, and assume that the spring is uncompressed before the mass is placed on the platform. In addition, assume that the spring is linear elastic with spring constant k. You may have solved these same problems using Newton’s second law when doing Prob. 3.16 and 3.17 — here use the work-energy principle to solve them.

Figure P4.49

If the mass m is gently placed on the spring scale (i.e., it is dropped from zero height above the scale), determine the maximum reading on the scale after the mass is released.