A track coach measures the 100-meter time of a track athlete. The runner completes the distance in 11.5 seconds. If the stopwatch has an uncertainty of 1.7%, what is the amount of uncertainty in the time?(1 point) 11.5 s ± 0.19 s
11.5 s plus or minus 0.19 s

11.5 s ± 0.20 s
11.5 s plus or minus 0.20 s

11.5 s ± 0.1955 s
11.5 s plus or minus 0.1955 s

11.5 s ± 0.196 s
11.5 s plus or minus 0.196 s

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".