高一物理第七题求解！
\u9ad8\u4e00\u7269\u7406\u7b2c\u4e03\u9898\u6c42\u89e3\u8c22\u8c22
\u671b\u91c7\u7eb3\u8c22\u8c22
\u56e0\u4e3a\u5f53\u7b2c5\u6ef4\u6c34\u8981\u843d\u4e0b\u65f6\uff0c\u7b2c\u4e00\u6ef4\u6c34\u521a\u597d\u843d\u81f3\u5730\u9762\uff0c\u6240\u4ee5\u6839\u636e\u4f4d\u79fb\u516c\u5f0f\u5f97\u51fa\uff1a\u5176\u95f4\u7684\u65f6\u95f4\u95f4\u9694\u4e3a\uff1a\u6839\u53f7\u4e0b\uff088m*2/10m/s^2\uff09=2/5\u500d\u6839\u53f710\u79d2\uff1b\u6240\u4ee5\u6ef4\u6c34\u7684\u65f6\u95f4\u95f4\u9694\u4e3a\uff1a\u6839\u53f710/10\u79d2\uff1b\u6240\u4ee5\u6b64\u65f6\uff0c\u7b2c\u4e8c\u6ef4\u6c34\u5df2\u7ecf\u4e0b\u843d\u4e86\uff1a3/10\u500d\u6839\u53f710\u79d2\uff1b\u518d\u6839\u636e\u516c\u5f0f\uff1aX=1/2gt^2\u5373\u53ef\u7b97\u51fa
\u672c\u9898\u5b9e\u9645\u4e0a\u53ef\u76f4\u63a5\u7528\u521d\u901f\u5ea6\u4e3a\u96f6\u7684\u5300\u52a0\u901f\u76f4\u7ebf\u8fd0\u52a8\u57281t\u5185\u30012t\u5185\u30013t\u5185....\u7684\u4f4d\u79fb\u6bd4\u7684\u5173\u7cfb\u4e3a1\u6bd44\u6bd49.....\u7684\u89c4\u5f8b\uff0c\u4e5f\u53ef\u7b97\u51fa\u7b54\u6848
相同位移时间比是1：√2-1：√3-√2..........
用1比时间就可以了
1:(√2+1):(√3+√2)
s=1/2at1^2 t1=根号2s/a
2s=1/2at2^2 t2=根号4s/a
3s=1/2at3^2 t3=根号6s/a
所以第一段用时t1=根号2s/a
第二段用时t二=根号4s/a-根号2s/a
第二段用时t三=根号6s/a-根号4s/a
再取倒数比
绛旓細鍙椾竴涓按骞冲垎鍔5Xcos37掳=4N锛屽瀭鐩村垎鍔5Xsin37掳=3N锛屽瀭鐩村垎鍔涗笌鐗╀綋閲嶅姏鍚堝姏F1=20N-3N=17N锛屽凡鐭ュ姩鎽╂摝鍥犳暟涓0.2锛屽垯鎽╂摝鍔涙槸3.4N锛屾按骞冲悎鍔涙槸F2=4N-3.4N=0.6N銆傛牴鎹墰椤跨X瀹氬緥锛孎=ma锛屽彲寰楁按骞冲姞閫熷害鏄痑=0.6N梅2kg=0.3锛屽凡鐭ュ彈鍔涙椂闂存槸4s锛屽垯4s鍚庨熷害鏄痸t=v0+at=0+0.3X4=1.2...
绛旓細F鍚戝績鍔=mv^2/R 锛團绌烘皵锛塣2=F鍚戝績鍔沕2+mg^2 浠ｅ叆瀛楁瘝灏卞ソ浜
绛旓細G-T=ma
绛旓細鐢辩涓涓潯浠讹紝璁惧埞杞︽椂闂翠负t1 鍙告満鍙嶅簲鏃堕棿涓簍 鍥犱负v=v0+at 鎵浠(200/9 )+at1=0 鍙堝洜涓簒=v0t+1/2at² 鍙緱(200/9)t+锛1/2锛塧t²1 鍚岀悊鍙互鐢辩浜岄棶寰楀嚭鍙︿竴涓柟绋嬬粍 鏈鍚庡寲绠绠楀嚭t鏃堕棿涓0.72s 涓嶆噦杩介棶銆
绛旓細x杞翠笂浠讳竴鐐圭殑鐢靛満寮哄害閮芥槸Q1鍜孮2鎵浜х敓鐨勭數鍦虹殑鍙犲姞锛岀敱浜嶲1澶т簬Q2锛屽彧鏈夊湪Q2鐨勫彸鏂瑰悎鐢靛満鎵嶆湁鍙兘涓洪浂銆傞氳繃璁＄畻鍙煡璇ョ偣绂籕2鐨勮窛绂讳负6cm銆傛湁鍙犲姞鍘熺悊鍙煡锛屽湪X杞翠笂0銆坸銆6鍜孹銆12鐨勫湴鏂癸紝鐢靛満寮哄害鐨勬柟鍚戞部X杞存柟鍚戙
绛旓細锛堜竴锛変袱涓川閲忓潎涓簃鐨勫畬鍏ㄧ浉鍚岀殑鐗╀綋锛屼腑闂寸敤缁宠繛鎺ワ紝鑻ョ怀鑳藉鎵垮彈鐨勬渶澶ф媺鍔涗负T锛岀幇灏嗕袱鐗╀綋鏀惧湪鍏夋粦姘撮潰涓婏紝鐢ㄦ媺鍔汧1鎷変竴鐗╀綋鏃讹紝鎭板ソ鑳藉皢杩炴帴缁虫媺鏂紱杩欐椂锛岀敱浜庢病鏈夋懇鎿︼紝鎵浠ヤ袱鐗╀綋鍔犻熻繍鍔紝鍏朵腑缁崇殑鎷夊姏T=ma1锛屾媺鍔汧1=2ma1,鎵浠1=2T锛堜簩锛夊樿嫢鎶婁袱鐗╀綋鏀惧湪绮楃硻姘村钩闈笂锛岀敤鎷夊姏F2鎷変竴鐗╀綋...
绛旓細锛1锛夊湪鏈楂樼偣鏃剁殑鏈灏忛熷害涓簐=鈭歊g 璁炬枩闈㈢殑楂樺害涓篽锛岀敱鏈烘鑳藉畧鎭掑緱 mgh=mg*2R+mv^2/2 h=5R/2 (2)鐢辨満姊拌兘瀹堟亽 mg*3R=mg*2R+mv^2/2 v=鈭2Rg 灏忕悆鍦˙鐐规椂浣跨敤鍚戝績鍔涘叕寮忓緱 FN+mg=nv^2/R FN+mg=2mgR FN=mgR 浜诧紝涓嶈蹇樿鍙婃椂閲囩撼鍝︺傛湁闂鍙﹁鎻愰棶锛屾垜浼氶殢鏃跺府鍔╀綘....
绛旓細鍥炵瓟锛歋=(1/2)*a*n^2-(1/2)*a*(n-1)^2 =(1/2)*a*(2n-1) a=2S/(2n-1)
绛旓細棣栧厛棰樼洰鐨勬剰鎬濇槸姹傛椂闂达紝鍙互璁炬暣娈典綅绉讳负2S,绗竴绉嶆儏鍐佃涓2t,閭ｄ箞2S=V1*t+V2*t,姹傚嚭t鐨勮〃杈惧紡2S/(V1+V2)绗簩绉嶆儏鍐电殑鏃堕棿涓=S/v1 +S/V2.鏃堕棿鐨勮〃杈惧紡姹傚畬鍚庯紝闅忎究V1,,V2鎵句袱涓暟瀛楀甫鍏ワ紙姣斿1鍜2锛夛紝绛旀灏卞嚭鏉ヤ簡锛欱 鐞嗚В鐨勮瘽璇烽噰绾虫垜 ...
绛旓細鍥炵瓟锛歮g-F=ma 鍙湁F涓涓湭鐭ユ暟,浠ｅ叆姹傚嚭鍗冲彲銆
