An object is moving along a horizontal coordinate line according to the formula s-1-1212 +211, where s, the directed distance from the origin, is in feet and 1 is in seconds (a) What are v(t) and a(t), the velocity and acceleration at time 1? (b) When is the object moving to the right? (c) When is the object moving to the left? (d) When is its acceleration negative? (a) v(t)= a(t)=