Answer : A Analysis : This question is intended to help students realize that the equation of a sphere cannot have the product xy or yz or xz in the equation. Options B , C , D are eliminated because they do not satisfy this condition and so of course A is the correct option. Question 4 : ...
Relative motion between the working surface of the center drill and the center hole causes the center hole to wear quickly, affecting accuracy. Figure 2-14: Rotating center point 4. Combined positioning In practice, people often use multiple surfaces as positioning standards at the same time. When ...
Oy // O 1 y 1 So the xy axis system has translational motion with respect to the x axis system 1 O 1 y 1 - For the xOy axis system, the flat plate has rotation around the O axis and the positioning angle is angle φ + When the plane moves, the parameters x 0 , y 0 , φ will change over time. We ...
