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1、选择题 速度为v的子弹,恰可穿透一块固定的木板,如果该类型子弹想要穿透9块同样固定的木板(子弹穿透木板时所受阻力视为不变),速度至少为
A.2v
B.3v
C.4v< ">
时间:2017-08-22 02:40:21
1、选择题 速度为v的子弹,恰可穿透一块固定的木板,如果该类型子弹想要穿透9块同样固定的木板(子弹穿透木板时所受阻力视为不变),速度至少为
A.2v
B.3v
C.4v
D.6v
2、计算题 如图所示,光滑水平面AB与竖直面内半圆形导轨在B点相接,导轨半径为R。一个质量为m的物体将弹簧压缩至A点后由静止释放,在弹力作用下物体获得某一向右速度,当它经过B点进入导轨瞬间对导轨的压力为其重力的7倍,之后向上运动恰能完成半圆周运动到达C点。求:
(1)弹簧的弹力对物体做的功;
(2)物体从B点运动至C点克服阻力做的功;
(3)物体离开C点后落回水平面时的动能。(空气阻力不计) 600)makesmallpic(this,600,1800);\' style=\"VERTICAL-ALIGN: middle\" src=\"http://www_php168_com/91files/2016060504/4hmsrrdoxz5.gif\">
3、计算题 如图所示,在长为L的轻杆中点A和端点B各固定一质量均为m的小球,杆可绕无摩擦的轴O转动,使杆从水平位置无初速释放摆下。求当杆转到竖直位置时,轻杆对A、B两球分别做了多少功? 600)makesmallpic(this,600,1800);\' style=\"VERTICAL-ALIGN: middle\" border=\"0\" src=\"http://www_php168_com/91files/2016060504/grrmcxfkjmb.gif\">
4、计算题 如图所示,粗糙的斜面600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/x4p5ofjpaon.png\" style=\"vertical-align:middle;\">下端与光滑的圆弧轨道
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/tncoemoxxie.png\" style=\"vertical-align:middle;\">相切于
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/taabk0k0v4m.png\" style=\"vertical-align:middle;\">,整个装置竖直放置,
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/dztlsm1330z.png\" style=\"vertical-align:middle;\">是最低点 ,圆心角
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/d3512vptiup.png\" style=\"vertical-align:middle;\">,
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/yf41kypzg5a.png\" style=\"vertical-align:middle;\">与圆心
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/skcbcr1add1.png\" style=\"vertical-align:middle;\">等高.圆弧轨道半径
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/gymbhqvsmck.png\" style=\"vertical-align:middle;\">0.5 m,斜面长
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/xbg2p04ibse.png\" style=\"vertical-align:middle;\">。现有一个质量
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/1axikkqvfc1.png\" style=\"vertical-align:middle;\">0.1 kg的小物体
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">从斜面
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/x4p5ofjpaon.png\" style=\"vertical-align:middle;\">上端
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/lwl0ykv2axh.png\" style=\"vertical-align:middle;\">点无初速下滑,物体
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">与斜面
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/x4p5ofjpaon.png\" style=\"vertical-align:middle;\">之间的动摩擦因数为
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/nfz1e45ih4s.png\" style=\"vertical-align:middle;\">(已知
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/eajuedbwac4.png\" style=\"vertical-align:middle;\">,g=10m/s2)。求:
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/02zlydx0fzf.jpg\" style=\"vertical-align:middle;\">
(1)物体600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">第一次通过
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/dztlsm1330z.png\" style=\"vertical-align:middle;\">点时的速度大小和对
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/dztlsm1330z.png\" style=\"vertical-align:middle;\">点处轨道的压力各为多大?
(2)物体600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">第一次离开
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/yf41kypzg5a.png\" style=\"vertical-align:middle;\">点后在空中做竖直上抛运动,不计空气阻力,则最高点
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/3vn45kyhsqm.png\" style=\"vertical-align:middle;\">和
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/yf41kypzg5a.png\" style=\"vertical-align:middle;\">点之间的高度差为多大?
(3)物体600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">从空中又返回到圆轨道和斜面.多次反复,在整个运动过程中,物体
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/g4zyllc5z5o.png\" style=\"vertical-align:middle;\">对
600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/dztlsm1330z.png\" style=\"vertical-align:middle;\">点处轨道的最小压力为多大?
5、选择题 初速度为零的下列粒子,经电压为U的同一加速电场加速后,动能最大的是
A.质子(600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/yakvxvhq0bf.png\" style=\"vertical-align:middle;\">)
B.α粒子(600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/ubydtili0rg.png\" style=\"vertical-align:middle;\">)
C.钠离子(600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/i0yxxj2jz2h.png\" style=\"vertical-align:middle;\">)
D.铝离子(600)makesmallpic(this,600,1800);\' src=\"http://www_php168_com/91files/2016060505/heuw12jmxh1.png\" style=\"vertical-align:middle;\">)