The following information is used for questions 8 and 9.
A flat disk rotates about an axis perpendicular to the plane of the disk and through the center of the disk with an angular velocity as shown in the graph below.
[asy]
size(400);
// x-axis
draw((0,0)--(12,0));
// x-axis tick marks
draw((4,0)--(4,-0.2));
draw((8,0)--(8,-0.2));
draw((12,0)--(12,-0.2));
//y-axis
draw((0,-3)--(0,5));
//y-axis tick marks
draw((-0.2,-2)--(0,-2));
draw((-0.2,0)--(0,0));
draw((-0.2,2)--(0,2));
draw((-0.2,4)--(0,4));
// y-axis labels
label("-2",(0,-2),2*W);
label("0",(0,0),2*W);
label("2",(0,2),2*W);
label("4",(0,4),2*W);
// Axis Labels
label("Time (s)",(10,0),N);
label(rotate(90)*"Angular Velocity (rad/s)",(0,1),6*W);
//Dashes
draw((0,4)--(12,4),dashed);
draw((0,2)--(12,2),dashed);
draw((0,-2)--(12,-2),dashed);
draw((4,-3)--(4,-1),dashed);
draw((4,0)--(4,5),dashed);
draw((8,-3)--(8,-1),dashed);
draw((8,0)--(8,5),dashed);
draw((12,-3)--(12,-1),dashed);
draw((12,0)--(12,5),dashed);
//Line
draw((0,4)--(12,-2));
// x-axis labels
label("1",(4,0),4*S);
label("2",(8,0),4*S);
label("3",(12,0),4*S);
[/asy]