The deflection profile $y(x)$ of a cantilever beam due to application of a point force $F$ (in Newton), as a function of distance $x$ from its base, is given by $y(x)=0.001F\;x^2[1-\frac{x}{3}]m.$ The angular deformation $\theta$ at the end of the cantilever is measured by reflecting a laser beam off a mirror $\text{M}$ as shown in the figure.
The translation $S$ of the spot of laser light on the photodetector when a force of $F=\text{1 N}$ is applied to the cantilever is
- $\text{1 mm}$
- $\text{3 mm}$
- $\text{6 mm}$
- $\text{12 mm}$