Suppose cars start at a car race. In how many ways can the top 3 cars finish the race?.

The slope of a velocity time graph over any interval of time gives the during that interval

Meaning of a nonzero y-intercept to a graph of reaction distance versus speed

Aparticle's position is given by x = 6.00 - 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".