The force constant \( k \) in Hooke's Law, which is expressed as \( F = kx \), where \( F \) is the force and \( x \) is the displacement, has the same dimension as force per unit displacement.
- The dimension of force \( F \) is given by:
\[
[F] = M L T^{-2}
\]
- The dimension of displacement \( x \) is:
\[
[x] = L
\]
So, the dimension of the force constant \( k \) is:
\[
[k] = \frac{[F]}{[x]} = \frac{M L T^{-2}}{L} = M L T^{-2}
\]
Thus, the dimension of the force constant is \( [M^1 L^1 T^{-2}] \).