一物体从斜面顶端由静止开始匀加速下滑到斜面底端。已知物体下滑的加速度a=0.2米每二次方秒，在最后
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0.5+\uff08-0.4*5\uff09= -1.5\uff08\u7c73\u6bcf\u79d2\uff09\u3002
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绛旓細鑻2:x1=7:3 鎵嶅彲鍋 鐢 X2-X1=1.2m; x2:x1=7:3 鍙В寰 x2=2.1m x1=0.9m 璁炬暣涓繃绋嬩腑鍔犻熷害涓篴 鍓3绉掑唴 0.9=(1/2)a*3^2 瑙ｅ緱a=0.2m/s^2 鍚3绉 璁総绉掓椂鍒拌揪搴曢儴 (1/2)*0.2*t^2-锛1/2)*0.2*(t-3)^2=2.1 瑙ｅ緱t=5 鎵浠鏂滃潯闀縮=(...
绛旓細鏈濂界敾涓浘,vt鍥惧儚,绗5s鏈=绗6绉掑垵,鎵浠ユ枩鐜囦负1,绔偣(0,0);(6,6)1锛氱4绉掓湯鐨勯熷害 5m/s 2锛氬ご7绉掑唴鐨勪綅绉 鍓7绉掔殑闈㈢Н 49/2m 3锛氱3绉掑唴鐨勪綅绉 4s鍖哄煙姊舰闈㈢Н 7/2m
绛旓細L=1/2at^2 a=2L/t^2 v=a*t/2=L/t
绛旓細(1)閿欙紝骞冲潎閫熷害=涓棿鏃跺埢鐬椂閫熷害=L/2t 锛2锛夊锛岃繖涓笉鐢ㄨВ閲婁簡鍚 锛3锛夊锛岀敾鍥撅紝鐩镐技涓夎褰㈠緱浣嶇Щ姣斾负1:2锛屾鏃舵椂闂翠笌涓偣鏃跺埢姣斾负1锛氾紙鏍瑰彿2锛/2锛鏂滈潰涓偣鐬椂閫熷害=锛圠/t锛*[1/(鏍瑰彿2/2锛塢 锛岃В寰椻垰2L/t 锛4锛夊锛屼笂棰樿В娉曪紝鍙緱 ...
绛旓細鏈夌墰椤跨浜屽畾寰 mgsinA-kmgcosA=ma 鈭鐗╀綋涓嬫粦鍔犻熷害鐨勫ぇ灏忎负 a=gsinA-kgcosA 鍙堢敱vt²=2as 鈭磛t²=2a(L/2)=2(gsinA-kgcosA)(L/2)=gl(sinA-kcosA)鈭寸墿浣撳埌杈鏂滈潰涓偣鐨勯熷害澶у皬涓 vt=鈭歔gl(sinA-kcosA)]
绛旓細璁鏂滈潰鎬婚暱2x.鏍规嵁鍒濋熷害涓洪浂鐨鍖鍔犻熺洿绾胯繍鍔ㄥ叕寮忥細x=1/2at^2鍒楀紡瀛愭湁x=1/2a*1^2.2x=1/2aT^2.瑙ｅ緱T锛濇牴鍙2.
绛旓細S1=0.36m锛宻2=0.84m S=锛坅t2锛/2 鐢╯1浠ｅ叆寰楀埌a=0.08 S=vot+锛坅t2锛/2 鐢╯2浠ｅ叆寰楀埌 vo=0.16 寰楀埌鎬绘椂闂存槸5s銆俈t=0.4 S=1m
绛旓細鎴戠殑浣滄硶锛氬拰浣犵瓟妗堢殑浣滄硶涓嶄竴鏍 === 鍏堟眰鍑簊1s2.s1 = 0.36绫 s2 = 0.48绫 s1 = 1/2 a(t1)^2 t1=3绉 鎵浠 = 0.08绫虫瘡骞虫柟绉 s2 = v1t1 + 1/2 a(t1)^2 = 3v1 + 0.36 鎵浠1 = 0.16绫虫瘡绉 v1 = v0 + at2 鍥犱负v0 = 0 鎵浠2 = 2绉 鎬绘椂闂磘 =...
绛旓細鏍规嵁閫熷害涓庝綅绉荤殑鍏崇郴鍏紡v2-v02=2ax鍒檝2=2aL锛寁鈥2=2a?L2锛岃В寰楋細v鈥=v2=22v锛涙晠绛旀涓猴細22v锛
绛旓細1 涓鐗╀綋鍦ㄦ枩闈㈤《绔敱闈欐寮濮嬪寑鍔犻熶笅婊戯紝鏈鍒3s鍐呴氳繃鐨勪綅绉绘槸4.5m锛屾渶鍚3s鍐呴氳繃鐨勪綅绉讳负10.5m锛屾眰鏂滈潰鐨勬婚暱搴.2 涓鐏溅娌垮钩鐩磋建閬擄紝鐢盇澶勮繍鍔ㄥ埌B澶勶紝AB鐩歌窛S锛屼粠A澶勭敱闈欐鍑哄彂锛屼互鍔犻熷害a1鍋氬寑鍔犻熻繍鍔紝杩愬姩鍒伴斾腑鏌愬C鏃朵互鍔犻熷害澶у皬涓篴2鍋氬寑鍑忛熻繍鍔紝鍒癇澶勬椂鎭板ソ鍋滄锛屾眰锛氾紙1锛...
