May someone please help me with my AP calculus review? I don't understand how to do these problems.

An object in rectilinear motion is modeled by the position function s(t) = 314 - 8+3 - 6+2 + 24t 1 > 0 where s is in feet (ft) and t is in seconds (s). Find the acceleration of the object when its velocity is zero. O -24 fu/s2, 36 ft/s2, and 72 ft/s2 only O -24 ft/s2 and 36 fu/s2 only 36 fu/s2 and 72 ft/s2 only 36 fu/s2 onlyIf the function 2ax2 + bx - 1 if x 3 is continuous for all real numbers x, then 18a - 9b = 1 19a - 9b = 1 19a + 15b = 1 19a - 15b = 1Find the slope of the tangent line to the graph of f(x) = xe* at the point (1, e). O 1 Oe2 O 2eLet h be defined by h (x ) = S f(x) . 8(x) if x 1 where f and g are both continuous at all real numbers. If lim f(x) = 2 and lim g(x) = -2, then for what number k is h x-1 x-1 continuous? O -5 C - 2 O N O - 4