文档介绍：【专题一】受力分析物体的平衡
[Topic 1] force analysis of the balance of objects
[test analysis]
1., the topics involved are: sliding friction, static friction and dynamic friction factor, deformation, elasticity, Hooke' s law, the synthesis and decomposition of forces.
"Outline" for "sliding friction, static friction, dynamic friction factor, deformation, elasticity and Hooke' s law" and other test sites are class I requirements: the "synthesis and decomposition of force" for the second class requirements.
Force is the basis of physics, is the content of college entrance examination. Among them, the probability of friction and Hooke's law is higher. Mainly related to spring problems, friction, etc., through the connector, stack and other forms of examination. The focus of the review is the synthesis and decomposition of forces, the concept of friction and the law of change.
College entrance examination hot 2. this topic is mainly composed of two aspects: the first is the friction of the problem, two is the two synthesis problem of concurrent force. The knowledge of this chapter is often examined in accordance with Newton's law, work and energy, electromagnetic fields, etc. . Simple examination of this chapter of multiple-choice questions, mostly medium difficulty.
[knowledge convergence]
gravity
: gravity is caused by ground objects on the earth
, but the two are not equivalent, as a component of gravity to provide the object with the rotation of the earth to. and another component that is gravity, as shown in the figure of gravity and centripetal force.
size: change with the change of geographical position
At the poles:
At the equator:
Generally, G=mg is near the ground surface
direction: vertical, downward, and not pointing to the center of the earth
elasticity
: contact conditions: the extrusion; the. deformation
size: spring, Newton's law and solved by
other elastic equilibrium conditions.
: the direction of the pressure and the supporting force in the d