12. A 50 kg Bungee jumper drops from a bridge with an initial speed of 0 m/s. The height from the bridge to the ground is 75 m. If the natural length of the bungee (i.e. spring) attached to the jumper is 1/3 of the height of the bridge, what is the minimum spring constant k that will prevent this jumper from touching the ground after jumping? (g=9.8 m/s2 )

a) 0.392 N/m b) 29.4 N/m c) 19.6 N/m d) 58.8 N/m

Please attach the explanation