$12\mathrm{.}5$ A loading car is at rest on a track forming an angle of $25$ with the vertical when a force is applied to the cable attached at $C.$ The gross weight of the car and its load is $5500lb,$ and it acts at point $G.$ Knowing the tension in the cable connected at $C$ is $5000lb,$ determine $($a$)$ the acceleration of the car. $($b$)$ the distance the car moves in $20s,($c$)$ the time it takes for the car to return to its original position if the cable breaks after $20s.$