The diagram above represents the graph of the force F applied in stretching a spiral spring against the corresponding extension (X). The force constant of the spring is
-
A.
20 Nm-1 -
B.
40 Nm-1 -
C.
30 Nm-1 -
D.
10 Nm-1
Correct Answer: Option A
Explanation
F = Ke (Hooks law)
K = F/e = 80/4
= 20 Nm-1