Answer:
40.6 N/m
Step-by-step explanation:
From Hooke's law we relate the extension of a spring and the applied force by the formula F=kx where F is the applied force, k is spring constant and x is extension of spring.
Making k the subject of the formula then we have

We also know that F=gm where g is acceleration due to gravity which we take as 9.81 m/s2 while m is the mass. Substituting F with gm into the formula we get that

Substituting m for 5.8 kg and x for 1.4 m we get the spring conatant as

Therefore, the spring constant is approximately 40.6 N/m