70-曲线运动 万有引力与航天（70 - curve motion gravitation and aerospace）.docVIP

70-曲线运动 万有引力与航天（70 - curve motion gravitation and aerospace） The curve of gravity and space (90 minutes, 100 out of 100) Proposition design The difficulty qid The target More easily medium A little difficult Horizontal cast 8 7, 13, 15 Circular motion 1, 2, 5, 9 6, 11 14 Law of universal gravitation 3, 4, 10 and 12 The integrated use of 16 1. A single choice question (5 points for each question, 35 points) 1. As shown in figure 1, the two wheels are driven by belts without skidding. There are A, B and C in the figure, which is the radius of the three points RA rB = rC, then the relationship between the centripetal acceleration aA, aB and aC of these three points is () A.a = aB = aC B.a C aA aB C a C aA aB figure 1 D. a C = aB aA Analytic: belt drive and sliding, point A to point B the same linear velocity, by A = have A ∝, so aA aB. Point A to point C coaxial rotation and angular velocity are the same, by A = 2 r know A ∝ omega r, so have aA aC, so aC aA aB, visible option C is correct. Answer: C 2. M is A small object that is transmitted on the horizontal conveyor belt (which can be considered as A particle) and A is the terminal belt Wheel, as shown in FIG. 2, is known that the pulley radius is r, and the conveyor belt will not play with the pulley When m can be thrown horizontally, the number of revolutions per second is the least () A. b. figure 2 C. D. Analysis: when m happens to be thrown horizontally only by gravity, the supporting force FN = 0. At the highest point, mg = m, V =. And v = 2 PI n dot r, n = =. Answer: A (3) (2009 · chongqing college entrance examination) according to the report charng-ers no.1 and chang e 2 craft work of circular orbit around the moon from the surface of the moon is about 200 km and 100 km respectively, running speed v1 and v2, respectively. Then, the ratio of v1 and v2 for (1700 km) radius of the moon () A. b. c. D. Analysis: G = m knowledge: v =, So = =, C is correct. Answer: C 4. (2009, jiangsu college entrance exami