A group of students performed a compression experiment where they placed weights on top of a cylinder of material and measured the change in the cylinder’s height. The cylinder had a radius of 2 cm, and an initial height of 10 cm. This group of students would like to know what kind of material their cylinder was. Based on their data shown below, and the Young’s modulus values shown, which of the materials below could the cylinder be made from? Select all that apply.

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".