(2006年四川理综)1（(2006 Sichuan Science) 1）.doc

(2006年四川理综)1（(2006 Sichuan Science) 1） Collected by oneself Mistakes are unavoidable For reference only In case of error Please correct me! Thanks (2006 Sichuan Science) 1.. The quality of spring is fixed on the lower end of a ball. The upper end of the spring hand make the ball readily in the vertical direction with the same size of the acceleration of a (ag) respectively upward and downward linear acceleration. If ignoring air resistance The elongation of the spring is respectively; if the air resistance can not be neglected and the size is constant The elongation of the springs is respectively A. B. C. D. (2006, Guangdong Physics) 2. the following incorrect understanding of motion is A. Aristotle believes that the natural state of the object is stationary It moves only when it is stressed B. Galileo argued that force is not the cause of the speed of an object C. Newton holds that the real effect of force always changes the speed of an object Not just to make it move D. Galileo deduced from the ideal experiment If there is no friction An object on a horizontal plane Always have a certain speed (2006 National Science 1) 3. (19 points) a level of light colored long conveyor belt placed a coal (taken as a particle) The coal conveyor belt and the friction factor between the initial mu. The conveyor belt and coal are static. Now let the belt movement with constant acceleration start A0 When its speed reaches v0 At this rate, it moves at a constant speed over a period of time The coal left a black mark on the belt after Relative to the coal conveyor belt slip. For this no longer black mark length. Explanation: according to the black mark on the conveyer belt The relative sliding between the conveyor belt and coal The acceleration is less than a A0 acceleration coal conveyor belt According to Newtons law Available 1. Set experience time t The belt begins at rest and accelerates to speed equal to v0 Coal is accelerated from rest to V Yes 2 3 Because so Coal continues to b