Current location - Plastic Surgery and Aesthetics Network - Plastic surgery and medical aesthetics - (20 12? Changzhou) As shown in the picture, two fingers press both ends of the pencil hard to keep it still. Which of the following statements is correct () A. Finger of the left hand
(20 12? Changzhou) As shown in the picture, two fingers press both ends of the pencil hard to keep it still. Which of the following statements is correct () A. Finger of the left hand
(1) The pencil is at rest, and the pressure exerted by two fingers is a pair of balanced forces. So the pressure exerted by the two fingers on the pencil is equal. Because the pressure exerted by the finger on the pencil and the pressure exerted by the pencil hand form a pair of acting force and reaction force, these two forces are also equal. So the two fingers exert the same pressure on the pencil.

(2) Because the stress on both ends of the pencil is the same, and the stress area on the right side is small, it can be seen from p=FS that the stress on the fingers of the right hand is larger.

So choose D.