The first section force
volume one
one
1D 2B 3C 4C 5C 6D
two
7 roles; Mutual; Newton; n；
8 size; Direction; Action point; Action effect
9 action point; When opening the door, the closer the hand is to the door axis, the more laborious it is.
10 motion state; Shape; mankind
1 1 mutual; Force can deform an object.
three
12 is a picture, so I can't draw it. Sorry.
four
13 Because the forces between objects are mutual, when people give a downward force to the horizontal bar, the horizontal bar also gives people a force of equal magnitude and opposite direction, that is, the human body will also be pulled upward by the horizontal bar, so the human body will move upward.
five
14 (1) 1 The action of the force is related to the magnitude of the force. The function of force is related to the direction of force.
(2) The action of force is related to the action point of force.
(3) Control variables
6 15 C
Volume b
one
1B 2D 3① direction of force; 2. The action point of force; B, C 3 force; D
two
4 deformation; Motion state (speed)
5A； b； action spot
6① Blow; Wind; Grass movement
② refraction; Fish; Load movement
7 on the contrary; Direction of force; Save effort; The shape of an object
three
8 on the contrary; The action of forces between objects is mutual (the state of motion in which forces can be changed); Make smaller
four
9 is a form. I don't know how to type it. Sorry.
10ACD
1 1 racket, ball
Whew, I'm exhausted, but I'm glad I helped you.