(4 points) A particle moves according to the law of motion s = 13 - 7+2 + 2t, +2 0, where t is measured in seconds and s in feet. a.) Find the velocity at time t. Answer: 3t* *2 - 14t + 2 b.) What is the velocity after 3 seconds? Answer: -13 c.) When is the particle at rest? Enter your answer as a comma separated list. Enter None if the particle is never at rest. Answer: 4.519146175,0.147520491 d.) When is the particle moving in the positive direction? When O S t