An amusement ride called the "corkscrew" takes the passengers through the upside-down curve of a horizontal cylindrical helix. The velocity of the cars as they pass position $A$ is $15 \mathrm{m} / \mathrm{s}$, and the component of their acceleration measured along the tangent to the path is $g \cos \gamma$ at this point. The effective radius of the cylindrical helix is $5 \mathrm{m},$ and the helix angle is $\gamma=40^{\circ} .$ Compute the magnitude of the acceleration of the passengers as they pass position $A$