Physics Question from JEE Main 2023 · 25 January, Shift 1

An object of mass $m$ initially at rest on a smooth horizontal plane starts moving under the action of force $F = 2N$. In the process of its linear motion, the angle $\theta$ between the direction of force and horizontal varies as $\theta = kx$, where $k$ is a constant and $x$ is the distance covered by the object from its initial position. The expression of kinetic energy of the object will be $E = \frac{n}{k} \sin \theta$. The value of $n$ is: