Hi, I can't find the right answers of these problems, can someone help me?

(1 point) Suppose that the equation of motion for a particle (where s is in meters and I in seconds) is s=3t33r (a) Find the velocity and acceleration as functions of 2'. Velocity at time I = Acceleration at time t = (b) Find the acceleration after 1 second. Acceleration after 1 second: (c) Find the acceleration at the instant when the velocity is D. Acceleration: \f(1 point) Suppose that f(x) = 111(4 + x2) (A) Use interval notation to indicate where f (x) is concave up. Note: When using interval notation in WeBWorK, you use I for 00, -l for 00, and U for the union symbol. If there are no values that satisfy the required condition, then enter "{}" without the quotation marks. Concave up: (B) Use interval notation to indicate where f (x) is concave down. Concave down: (0) Find all inflection points of f . If there are no inflection points, enter 1000. If there are more than one, enter them separated by commas. Inflection point(s) at x =