Answer
$357.51\ m/s$
Work Step by Step
Linear velocity is $v=y\omega$ (where $y=r\ cos\theta$).
Here, $r$ is radius of earth and is equal to $6400\ km$.
Therefore;
$v=\omega r cos (40)$
$v=(7.292\times 10^{-5}\ m/s)(6400\times 10^3 \ m) (0.766)$
$v= 357.51\ m/s$
