A spring has a length of 0.190 m when a 0.300 kg mass hangs from it, and a length of 0.750 m when a 2.80 kg mass hangs from it.

(a) What is the force constant of the spring?

(b) What is the unloaded length of the spring?

2 answers

F=kx

.3*g=k(.190-u)
2.80g=k(.750-u) u is the unstretched length.

solve for k.
What is the unstretched length?