When a 2.5 kilogram object is hung vertically on a certain light spring described in Hooke's law, the spring stretches 2.76cm.
(a) Determine the force constant of the spring?
(b) If the 2.5 kilogram object is removed, find how far will the spring stretch if a 125 kilogram block is hung on it?
(c) Determine how much work must an external agent do to the same spring 8.00 cm from its unstrehed position?