He removes two strips of tape from the roll. He presses each strip of tape, sticky-side down, on a plastic surface.
He quickly removes each strip of tape from the plastic surface.
Ike's teacher tells him that this process has caused each strip of tape to gain a negative electric charge. What could Ike do next to demonstrate that the negative charge of each strip has generated an electric field?

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".