Every year, new records in track and field events are recorded. let's take an historic look back at some exciting races.

in 1989, carl lewis established a world record when he ran the 100. meter dash in 9.92 seconds. what was his average speed (in m/s) for the race? remember to include your data, equation, and work when solving this problem.

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".