JEE Physics Practice Question

A solid horizontal surface is covered with a thin layer of oil. A rectangular block of mass $m=0.4 \mathrm{~kg}$ is at rest on this surface. An impulse of $1.0 \mathrm{~N}$ is applied to the block at time $t=0$ so that it starts moving along the $x$-axis with a velocity $v(t)=v_{0} e^{-t / \tau}$, where $v_{0}$ is a constant and $\tau=4 \mathrm{~s}$. What is the displacement of the block, in metres, at $t=\tau$? Take $e^{-1}=0.37$