The $y-$component of the weight pushes the cart onto the incline. Notice that the $x-$component pulls the cart down the incline. It is this $x-$component of the weight, $w_x,$ that will accelerate the cart. The challenge now is to determine the $x-$component, $w_x$

Notice that the weight, $w,$ and its components, $w_x$ and $w_y,$ make a $3-4-5$ right triangle. Compare this triangle with the standard $3-4-5$ triangle. Use similar triangles to find $w_x.$

$w_x=,N$

Calculate the acceleration of the cart using Newton's $2^{nd}$ law and the component of the weight, $w_x$ above. Record as a below.

$a=\frac{F_{\text{n}\text{e}\text{t}}}{m}=\frac{w_x}{m}$

$a=,\frac{m}{s^2}$