When driving in heavy rain, or on a flooded road, your tires can ride on a thin film of water like skis;
a. if you don't slow down, you can easily lose control and skid.
b. if you are driving a full-size vehicle, this will not happen unless you are driving much faster than the speed limit.
c. if you are an average driver, you can safely drive at the speed limit in these conditions?

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".