Q.7. The disk is rotating about an axis parallel to thickness. The line AB is undergoing

1. pure translation
2. pure rotation
3. combined rotation and translation
4. oscillation

Q.8. The instantaneous center of rotation of a cylinder in pure rolling motion is

1. at the center of the cylinder
2. at infinity
3. at the point of contact of the cylinder and surface on which it rolls
4. at a distance of half the radius from the center.