Answer:
(a) 1.2 N/cm
(b) 8.4 Newtons
(c) 19.2 cm
Step-by-step explanation:
Since the formula is already given as Force=K*x then
and

(a)
Substituting F with 12 N and x with 10cm we obtain

(b)
Using spring constant obtained in part (a) then K=0.12 N/cm and x is given as 7cm then
Force=k*x=1.2 N/cm*7 cm=8.4 Newtons
(c)
and F is given as 23 N and using same spring constant
