Kiley went 5.7 km/h north and then went 5.8 km/h west. from start to finish, she went 8.1 km/h northwest. which best describes her numbers? 5.7 km/h north and 5.8 km/h west are instantaneous speeds, while 8.1 km/h northwest is the average speed. 5.7 km/h north and 5.8 km/h west are average speeds, while 8.1 km/h northwest is the instantaneous speed. 5.7 km/h north and 5.8 km/h west are average velocities, while 8.1 km/h northwest is the instantaneous velocity. 5.7 km/h north and 5.8 km/h west are instantaneous velocities, while 8.1 km/h northwest is the average velocity.

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".