小班讲义高一物理第14讲运动的合成与分解

1、龙 文 教 育精品小班课程辅导讲义讲义编号 2013秋季 辅导科目： 物理 年级： 高一课 题第14讲：运动的合成与分解教学目标教学重点、难点教学内容1、运动的合成与分解（1）、合运动与分运动：合运动就是物体的 ，而物体的实际运动过程中，又可以看作物体同时参与了几个运动，这几个运动就是物体实际运动的 （2）、思考运动合成与分解的运算法则： （3）、思考合运动与分运动的关系： a、等效性各分运动的规律叠加起来与合运动规律有相同的效果 b、独立性某方向上的运动不会因为其他方向上的运动而影响自己的运动性质 c、等时性合运动通过合位移所需时间和对应的每个分运动通过分位移的时间相等，即各分运动总是同2、

2、小船过河问题：（船在静水中的速度为v船，河水的水流速度v水，河宽为d）“两最”问题一最：最短过河时间二最：最短过河位移1、某人以一定速率垂直河岸向对岸游去，当水流运动是匀速时，他所游过的路程、过河所用的时间与水速的关系是 ( )a水速大时，路程长，时间长 b水速大时，路程长，时间短c水速大时，路程长，时间不变 d路程、时间与水速无关2、小船在静水中的速度为5m/s，它在一条流速为4m/s、河宽为150m的河流中渡河，则（ ）a、小船保持船头与河岸垂直方向行驶，只需30s就可以到达对岸b、小船若在30s的时间内渡河，则一定是到达正对岸c、小船若以最短距离渡河，所用的时间为30sd、渡河中若水流突

3、然增大至大于小船在静水中的速度，则小船不能到达河岸3、如图所示，一艘炮艇沿长江由西向东快速行驶，在炮艇上发射炮弹射击北岸的目标要击中目标，射击方向应 ( )a 对准目标 b偏向目标的西侧c偏向目标的东侧 d无论对准哪个方向都无法击中目标4、用跨过定滑轮子绳把湖中小船拉靠岸，如图所示，已知拉绳的速度v不变，则船速（ ）a、不变 b、逐渐增大c、逐渐减小d、先增大 后减小5、一小船在200m宽的河中横渡到对岸，已知水流速度是2m/s，小船在静水中的速度是4m/s。求(1)它渡河最短时间为多少?(2)如果要以最短时间渡河，船头应指向何方？此时渡河位移多少?(3)要以最短位移渡河，船头又指向何方？此时

4、渡河时间是多少？v1v2图4-26、某人骑自行车以10m/s的速度在大风中向东行使，他感觉到风正以相当于车的速度从北方吹来，实际上风的速度是（ ）a14m/s，方向为南偏西45 b14m/s，方向为北偏东45c10m/s，方向为正北 d10m/s，方向为正南7、如右图所示汽车以速度v匀速行驶，当汽车到达某点时，绳子与水平方向恰好成角，此时物体m的速度大小是多少？3.课堂练习8、小船在静水中速度为v ，现小船要渡过一条河流，渡河时小船垂直对岸划行,若小船划行至河中间时,河水流速忽然增大,则渡河时间与预定时间相比,将( )a、增长 b、不变 c、缩短 d、无法确定9、一条河宽500m，河水的流速是

5、3m/s，一只小艇以5m/s（静水中的速度）的速度行驶，若小艇以最短的时间渡河，所用的时间是_s，若小艇要以最短航程渡河，所需的时间是_s 第 14 次课后作业学生姓名： 一、单项选择题(共3题)1.河宽100m，水流速度为3ms，一条小船在静水中的速度为5ms，关于船过河的过程，下列说法正确的是a船过河的最短时间是25sb船要垂直河岸过河需用20s的时间c船不可能垂直河岸过河d只要不改变船的行驶方向，船过河一定走一条直线2.小船欲前往对岸，船速为4m/s，水速为3m/s，则船的实际速度大小为_m/s。二、多项选择题(共16题)1.一船在静水中速率是6m/s,要横渡宽为180m.水流速度为8m

6、/s的河流，则下述说法中正确的是 a.船相对于地的速度一定是10m/s b.此船过河的最短时间是30sc.此船可以在对岸的任一点靠岸 d.此船不可能到达对岸2.如上图，在河岸上用细绳拉船，为了使船匀速靠岸，拉绳的速度必须是 a加速拉b减速拉c匀速拉d先加速后减速拉3.关于直线运动的合成，下列说法正确的是a.两个直线运动的合运动一定是直线运动b.两个直线运动的合运动可能是直线运动c.两个直线运动的合运动一定是曲线运动d.两个直线运动的合运动不可能是曲线运动4.关于匀加速直线运动的合成，下列说法正确的是a.两个匀加速直线运动的合运动一定是曲线运动b.两个匀加速直线运动的合运动一定是直线运动c.两个

7、匀加速直线运动的合运动可能是曲线运动d.两个匀加速直线运动的合运动不可能是直线运动5.关于初速为零的匀加速运动的合成，下列说法正确的是 a.两个初速为零的匀加速直线运动的合运动一定是直线运动b.两个初速为零的匀加速直线运动的合运动只有在一定条件下才可能是直线运动c.两个初速为零的匀加速直线运动的合运动可能是曲线运动d.两个初速为零的匀加速直线运动的合运动一定是曲线运动6.关于一个匀速直线运动和一个匀加速直线运动的合成，下列说法正确的是a.一个匀速直线运动和一个匀加速直线运动的合运动一定是曲线运动b.一个匀速直线运动和一个匀加速直线运动的合运动可能是直线运动c.一个匀速直线运动和一个初速为零匀加

8、速直线运动的合运动一定是直线运动d.一个匀速直线运动和一个初速为零匀加速直线运动的合运动一定是曲线运动7.关于互成锐角的一个匀速直线运动和一个匀变速直线运动的合运动正确的说法是a.一定是直线运动 b.一定是曲线运动c.可以是直线也可能是曲线运动 d.以上说法都不正确8.某人坐在速度为15m/s，向正东方向行驶的汽车上，觉得风以20m/s的速度从正南吹来，实际风速是 a.17.5m/s向东偏北 b.25m/s向西偏北c.25m/s向西偏南 d.25m/s向东偏北9.关于运动的合成与分解，下列说法中正确的是a.两个速度大小不等的匀速直线运动的合运动，一定是匀速直线运动b.两个直线运动的合运动一定是

9、直线运动c.合运动是加速运动时，其分运动中至少有一个是加速运动d.合运动是匀变速直线运动时，其分运动中至少有一个是匀变速直线运动10.某人乘小船以一定的速率垂直河岸向对岸划去，当水流匀速时，关于他过河所需的时间、发生的位移与水速的关系正确的是a水速小，位移小，时间短b水速大，位移大，时间短c水速大，位移大，时间不变d位移、时间与水速无关11.一小船以恒定的航速渡河，当行至河中央时，水流速度突然变大，则小船渡河时间将 a增大 b减小 c不变 d不能确定12.关于轮船渡河，正确的说法是a.水流的速度越大，渡河的时间越长b.欲使渡河时间越短，船头的指向应垂直河岸c.欲使轮船垂直驶达对岸，则船相对水的

10、速度与水流速度的合速度应垂直河岸d.轮船相对水的速度越大，渡河的时间一定越短13.设船速为v1，水流速度为v2，t为船渡河的时间，若v1与v2垂直，则av1的大小一定时，v2越大，t越小 bt与v2无关c只有v1、v2同时增大，t才会减小 dv1增大，v2同时减小，t不一定减小14.关于匀速直线运动的合成，下列说法正确的是a.两个匀速直线运动的合运动一定是直线运动b.两个匀速直线运动的合运动可能是直线运动c.两个匀速直线运动的合运动一定是曲线运动d.两个匀速直线运动的合运动可能是曲线运动15.河宽420m，船在静水中的速度为4ms，则船过河的最短时间为a140s b105s c84s d60s

11、16.某人站在电动扶梯上，经过时间t1从一楼升至二楼，如果电动扶梯不动，此人沿着扶梯从一楼走至二楼的时间为t2。现使扶梯正常运动，人也保持原来的速度向上走，则人从一楼到二楼的时间是a b c d三、非选择题（填空）(共7题)1.人在小船上向右前进了5m，同时船向后退了3m，则人相对于岸的位移是 。2.飞机以40m/s的速度向西飞行，同时有南风，风速为10m/s，则飞机的实际速度大小为m/s。3.降落伞在下落一段时间后的运动是匀速的，无风时，某跳伞员着地速度是4ms。现在由于有沿水平方向向东的风的影响，跳伞员着地的速度变为5ms，那么风速为_。4.如下图，汽车以速度v匀速行驶，当汽车到达p点时，

12、绳子与水平方向的夹角为，此时物体m的速度大小为_。5.无风天下雨,雨滴落地速度v1=4m/s,水平行驶的小车速度为v2=3m/s,雨滴相对小车的速度是_。 待添加的隐藏文字内容26.船在静水中的速度为l0kmh，水流的速度为5kmh，船从码头出发到下游30km的另一码头需要行驶h。7.雨点以3ms的速度竖直下落，在水平地面上匀速行走的人，看到雨点下落的方向和竖直方向成30角，则人的速度的大小为ms。8.飞机在航空测量时，它的航线要严格地从西到东。如果飞机的速度是80kmh，风从南面吹来，风的速度为40kmh，那么飞机所测地区长为80km，需要时间为。四、非选择题（解答）(共1题)1.一圆周长为

13、4m，质点沿着这个圆周运动，当它通过1m弧长时速度方向改变了多少度?位移多大?一1答案：d 2答案：5 二1答案：b 2答案：b 3答案：b 4答案：c 5答案：a 6答案：b 7答案：b 8答案：d 9答案：a c d 10答案：c 11答案：c 12答案：b 13答案：b 14答案：a 15答案：b 16答案：b 三1答案：向右2m 2答案： 3答案：3m/s 4答案： 5答案：5m/s 6答案：2 7答案： 8答案：2h 四。1答案：mwinger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win

14、over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their f

15、irst pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most in

16、terest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this

17、weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorro

18、w and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of

19、 european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: missi

20、on aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will m

21、ove through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratos

22、phere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got

23、caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands josh charnley in the opening game of the tournament.that c

24、ould be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-ch

25、ase. theyve been great at all the unglamorous stuff that often goes unnoticed in the stands but not by your team-mates.it is as though their entire tournament has been preparation for the final.in johnathan thurston, cooper cronk, cameron smith and either billy slater or greg inglis at full-back the

26、y have a spine that is unmatched in rugby league. they have played in so many high-pressure games - a priceless asset going into saturday.the kiwis are a lot less experienced but winning a dramatic match like their semi-final against england will do wonders for their confidence.they defeated austral

27、ia in the four nations final in 2010 and the last world cup, and know they can rise to the big occasion.winger tuivasa-sheck, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recov

28、ering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with n

29、ine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of the year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first pl

30、ayer to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskf

31、orce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him

32、first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said the

33、y were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. s

34、tarting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb highe

35、r than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an olympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five year