A particle moves according to the law of motion s=-8+31, 10, where t is measured in seconds and s in feet. (a) Find the average velocity over the interval [1,2] Answer: -14 (b) Find the velocity at time t. ft S Answer: 3t^2-16t+3 (c) What is the velocity after 3 seconds? Answer: -18 ft S ft S (d) What is the acceleration after 7 seconds? Answer: 26 ft $2 (e) Fort 0, when is the particle moving in the positive direction? Answer: