The position of a particle moving on a horizontal line (where s is in feet to the right of a fixed reference point and t is in seconds after the start of the observation) is s(t) = t 8t+20, t0. (A) Find the velocity, in feet per second, at time t: v(t) = = (B) Find the velocity (in ft/sec) of the particle at time t = 3. (C) Find all values of t for which the particle is at rest. (If there are no such values, enter none. If there are more than one value, list them separated by commas.) t = (D) Use interval notation to indicate when the particle is moving in the positive direction. (If needed, enter inf for . If the particle is never moving in the positive direction, enter none.) (E) Find the total distance (in feet) traveled during the first 8 seconds.