a ball is projected on smooth inclined plane in direction perpendicular to line of greatest slope with velocity of 8m/s. find its speed after 1 sec

There are horizontal and vertial components acting.
Assuming the angle of inclination with which the ball was thrown is 45 degrees.
The initial speed along x- axis is
$$\begin{gathered} u \cos \theta \\ and along y is u \sin \theta . \\ The horizontal component does\text{'}t change. \\ The vertiacal after one second is u \sin \theta -g\left(1\right). \\ 8/\sqrt{2-9.8 =}5.65-9.8 = 4.15 m/s \\ The resul\tan t is \sqrt{4.{15}^2+5.{65}^2} \\ 5.65 m/s. \end{gathered}$$