The work done in extending a spring by 40 mm is 1.52J. Calculate the elastic constant of the spring.

A.

38.8 Nm-1

B.

60.8 Nm-1

C.

190.0 Nm-1

D.

1900.0 Nm-1

E.

3800.0 Nm-1

Correct answer is D

Force = Elastic constant x extension

Work done = \(\frac{1}{2} K \times e^2\)

Given Work done = 1.52J; Elastic constant (k) = ?; e = 40mm = 0.04 m

\(\therefore 1.52 = \frac{k \times (0.04)^2}{2}\)

\(3.04 = k \times 1.6 \times 10^{-3}\)

\(k = \frac{3.04}{1.6} \times 10^3\)

= 1.9 x 10\(^3\)

= 1900 Nm\(^{-1}\)