You are driving a car behind another car. both cars are moving at speed 80 km/h. take the reaction time of the driver in car 2 is 0.60 s. assume car 2 brakes are just a bit harder than car 1 brakes. what minimum distance behind the car in front should you drive so that you do not crash into the car's rear end if the driver of that car slams on the brakes?

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".