The coefficient of static friction between a rubber tire and the road surface is 0.85. What is the maximum acceleration of a 1042-kg four-wheel-drive truck if the road makes an angle of 12.7° with the horizontal when the truck is the following.
Standard inclined plane stuff. Fg = 1024kg * 9.8 m/s^2. Fn = Fg * cos 12.7. Ffric = 0.85*Fn.
Ffric = Force applied to car by street. But is opposed by component of gravity when going up hill, and a aided by gravity when descending.
Fgx = 1024*9.8m/s^2 * sin 12.7.
(a) ascending: Fnet = Fgx - Ffric a = Fnet/m
(b) descending: Fnet = Fgx + Ffric a = Fnet/m