You have a light spring which obeys Hooke's law. This spring stretches 2.52 cm vertically when a 2.80 kg object is suspended from it. Determine the following.

(a)the force constant of the spring (in N/m)

(b)the distance (in cm) the spring stretches if you replace the 2.80 kg object with a 1.40 kg object

(c)the amount of work (in J) an external agent must do to stretch the spring 7.90 cm from its unstretched position