planet Q moves in a fairly elliptical orbit around the sun.Planet Q‘s speed is 35.2km/s when it is at its most distant point ,7.68x10^10 m from the sun.How far is planet Q from the sun at its closest point ,where tis speed is 83.0km/s?

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planet Q moves in a fairly elliptical orbit around the sun.Planet Q‘s speed is 35.2km/s when it is at its most distant point ,7.68x10^10 m from the sun.How far is planet Q from the sun at its closest point ,where tis speed is 83.0km/s?
planet Q moves in a fairly elliptical orbit around the sun.Planet Q‘s speed is 35.2km/s when it is at its most distant point ,7.68x10^10 m from the sun.How far is planet Q from the sun at its closest point ,where tis speed is 83.0km/s?

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与压力是相互垂直的,然后,摩擦力分静摩擦和动摩擦两种,动摩擦的大小与正压力是成正比的,就是f=μN.而静摩擦力则不一样,最大静摩擦力往往比最大滑动摩擦要大一点,而且静摩擦的方向和大小是不定的,大多出现在平衡状态中,而滑动摩擦力是与运动方向相反的,影响它的大小的主要有两个因素,一个是正压力的大小,另一个就是μ的大小,而μ的大小是由接触面的粗糙程度决定的,也就是接触的两个面的材料的原因
影响摩擦力的因素不同情况不一样，动摩擦力、最大静摩擦力一般由两相互接触的物间的正压力以及两相互接触物的材料、表面性质、接触方式决定；但静摩擦力就与上述无关，它是由使物体发生相对运动趋势的合外力决定。一般情况下摩擦力与接触面无关，但实际上接触面会影响正压力的大小，即当压强一定时，接触面大，正压力会随着增大，这时，摩擦力就与接触面积有关了。要注意的是，很多情况下是压力一定，当面积变化时，压强也随着反比例变化，这时面积对摩擦力就无影响。
1. 摩擦力的大小与接触面间的压力大小有关，接触面粗糙程度一定时，压力越大摩擦力越大。生活中我们有这样的常识，当自行车车胎气不足的时候，骑起来更费力一些。
2. 摩擦力的大小与接触面的粗糙程度有关，压力一定时，接触面越粗糙，摩擦力越大。
拔河比赛比的是什么？很多人会说：当然是比哪一队的力气大喽！实际上，这个问题并不那么简单。
对拔河的两队进行受力分析就可以知道，只要所受的拉力小于与地面的最大静摩擦力，就不会被拉动。因此，增大与地面的摩擦力就成了胜负的关键。首先，穿上鞋底有凹凸花纹的鞋子，能够增大摩擦系数，使摩擦力增大；还有就是队员的体重越重，对地面的压力越大，摩擦力也会增大。大人和小孩拔河时，大人很容易获胜，关键就是由于大人的体重比小孩大。
另外，在拔河比赛中，胜负在很大程度上还取决于人们的技巧。比如，脚使劲蹬地，在短时间内可以对地面产生超过自己体重的压力。再如，人向后仰，借助对方的拉力来增大对地面的压力，等等。其目的都是尽量增大地面对脚底的摩擦力，以夺取比赛的胜利
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planet Q moves in a fairly elliptical orbit around the sun.Planet Q‘s speed is 35.2km/s when it is at its most distant point ,7.68x10^10 m from the sun.How far is planet Q from the sun at its closest point ,where tis speed is 83.0km/s? 英语翻译If we imagine a flat plane with the sun in the center and the planet revolving around it,the Earth slowly moves in and out of the flat plane by a few degrees,repeating the cycle every 100000years.还有这句话中FLAT PLANE是什么东 In search of a lonely planet文章翻译 we know that we are on a planet-------among other planets around the sunA moves B moved C moving Dto move Live in the moment.love in heart,between a moment,moves itself. moves the building _____south A.face B.faces C.facing D.face toPeter _______this house in September.A.moves B.moves into C.moved D.moved into Chinese who moves to a foreign country lives in Chinatowns,这句话对吗? 什么英文单词的英文解释是an object that moves around a bigger object in space Don't read in a_____car or bus.A to move B moves C moving D moved 一道关于角动量的题A uniform,spherical planet of mass M and radius R moves SLOWLY with an essentially uniform speed v through a cloud of interstellar dust particles,whose density is ρ.The dust particles are attracted towards the planet,and s She moves in her own way 歌词 hello everyone in our planet中文是什么意思 But his father gets a job in a big city ,and he moves there with his family 翻译Today,we take a virtual walk down a famous street found in almost every land on the planet. as a _r____you must be careful in the streets,because the traffic moves on the left首字母填空 A very big thing in space that moves around the sun or another stars.What is it?It is____. 一道SAT2物理题,Q:When a woman pushes on her grocery cart,the woman moves because of ()the answer is the force that the ground exerts on the woman.In light of the net force,the woman horizontally gets the opposite reaction from the cart and the f