求几题高一物理运动学难题? 高一物理难题(运动学)
\u9ad8\u4e00\u7269\u7406\u8fd0\u52a8\u5b66\u96be\u9898\u89e3\uff1a\u5217\u8f66\u9a76\u8fc7\u4ea4\u53c9\u70b9\u7528\u65f6\uff1at =l2+s2 v2
t=25s
\u82e5\u6c7d\u8f66\u572825s\u5185\u4f4d\u79fb\u4e3as1=175m
\u5219\uff1av1t-1 2 at2=s1a=0.64m/s2
\u6b64\u65f6\u3000v=v1-atv=-1m/s\u56e0\u6b64\u6c7d\u8f66\u5df2\u7ecf\u572825s\u524d\u51b2\u8fc7\u4e86\u4ea4\u53c9\u70b9\uff0c\u53d1\u751f\u4e86\u4ea4\u901a\u4e8b\u6545\uff0c\u4e0d\u5408\u9898\u610f\uff0e\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000\u3000
\u8981\u4f7f\u6c7d\u8f66\u5b89\u5168\u51cf\u901f\uff0c\u5fc5\u987b\u5728\u5c0f\u4e8e25s\u7684\u65f6\u95f4\u5185\u6c7d\u8f66\u901f\u5ea6\u51cf\u5c11\u4e3a\u96f6\uff0c\u8fd9\u6837\u624d\u80fd\u4f7f\u5b83\u7684\u4f4d\u79fb\u5c0f\u4e8e175m
\u7531 v12=2as1
\u5f97 a=
9
14
m/s2=0.643m/s2
\u6c7d\u8f66\u51cf\u901f\u7684\u52a0\u901f\u5ea6\u81f3\u5c11\u4e3a\u30000.643m/s2\uff0e
\u6545\u672c\u9898\u7b54\u6848\u4e3a\uff1a0.643m/s2\uff0e
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\u4f46\u662f\u65f6\u95f4t\u600e\u4e48\u6c42\u5462\uff1f\u539f\u9898\u7ed9\u4f60\u524d\u4e09\u79d2\u548c\u540e\u4e09\u79d2\uff0c\u6839\u636e\u52a0\u901f\u5ea6\u516c\u5f0f\uff0c\u5217\u4e24\u4e2a\u65b9\u7a0b\uff0c\u5f88\u5bb9\u6613\u5c31\u4f1a\u628at\u6c42\u51fa\u6765\u3002\u89e3\u9898\u8fc7\u7a0b\u5982\u4e0b
\u5df2\u77e5\u5c0f\u7269\u4f53\u76f8\u5bf9\u4e8e\u5c0f\u8f66\u5728\u524d\u4e09\u9762\u6ed1\u884c4.5\u7c73\u8fd9\u4e2a\u6761\u4ef6\u6211\u4eec\u53ef\u4ee5\u6c42\u51fa\u6b64\u65f6\u5c0f\u8f66\u7684\u52a0\u901f\u5ea6\uff0c\u56e0\u4e3a\u8fd9\u65f6\u662f\u76f8\u5f53\u4e8e\u5c0f\u8f66\u5bf9\u7269\u4f53\u505a\u521d\u901f\u5ea6\u4e3a\u96f6\u7684\u5300\u52a0\u901f\u76f4\u7ebf\u8fd0\u52a8\uff0c\u75281/2at^2=s(4.5m)\u53ef\u77e5\u6b64\u65f6\u7684\u52a0\u901f\u5ea6a1\u7b49\u4e8e1m/s^2\uff0c\u7136\u540e\u540e\u4e09\u79d2\u505a\u521d\u901f\u5ea6\u4e0d\u4e3a\u96f6\u7684\u5300\u52a0\u901f\u76f4\u7ebf\u8fd0\u52a8\uff0c\u7528vt+1/2at^2=s(10.5m)\u53ef\u5f97\u521d\u901f\u5ea6\u4e3a2m/s\uff0c\u90a3\u4e48\u4e4b\u524d\u8fd0\u52a8\u7684\u65f6\u95f4t=v/a=2s\u3002\u800c\u52a0\u4e0a\u540e\u9762\u7684\u4e09\u79d2\u5c31\u662f\u539f\u9898\u4e2d\u7684t=5s
\u73b0\u5728\u5c31\u597d\u505a\u4e86\uff0c\u5c0f\u8f66\u7684\u5e95\u677f\u957f\u5c31\u7b49\u4e8e\u5c0f\u8f66\u76f8\u5bf9\u7269\u4f53\u79fb\u52a8\u7684\u8ddd\u79bb\uff0c\u7528s=1/2at^2\u8fd9\u4e2a\u516c\u5f0f\u53ef\u5f97s=12.5m
\u5c0f\u7269\u4f53\u79fb\u52a8\u8ddd\u79bb\u5c31\u662f\u4e4b\u524d\u548c\u5c0f\u8f66\u4e00\u8d77\u52a0\u901f\u7684\u8ddd\u79bb\u52a0\u4e0a\u540e\u9762\u7ef3\u5b50\u65ad\u4e86\u4ee5\u540e\u79fb\u52a8\u7684\u8ddd\u79bb\uff0cS\u603b=S\u524d+S\u540e\u3002S\u540e=vt=10m\uff0c\u56e0\u4e3a\u540e\u9762\u5c0f\u7269\u4f53\u505a\u5300\u901f\u76f4\u7ebf\u8fd0\u52a8\u3002S\u524d\u4f60\u5f97\u6c42\u51fa\u4e4b\u524d\u5c0f\u8f66\u548c\u7269\u4f53\u4e00\u8d77\u7684\u52a0\u901f\u5ea6\uff0c\u7528a=v/t=2/4=0.5m/s^2\uff0c\u7136\u540e\u6c42\u51faS\u524d=1/2at^2=4m\u3002\u8fd9\u6837S\u603b=4+10=14m
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18.物体以10 m/s的初速度冲上一足够长的斜坡,当它再次返回坡底时速度大小为6 m/s,设上行和下滑阶段物体均做匀变速运动,则上行和下滑阶段,物体运动的时间之比多大?加速度之比多大?
绛旓細1.涓杈嗘苯杞︿粠杞︾珯鍑哄彂鍋氬寑鍔犻杩愬姩锛岀粡杩10s閫熷害杈惧埌108km/h 姹傚姞閫熷害2.鍦ㄩ珮閫熷叕璺笂姹借溅鍋氬寑鍔犻熻繍鍔紝缁3min閫熷害浠54km/h鎻愰珮鍒144km/h姹傚姞閫熷害 3.娌垮厜婊戞按骞冲湴闈互12m/s閫熷害杩愬姩鐨勫皬鐞冿紝鎾炲鍚庝互鍘熼熷害澶у皬鍙嶅脊锛屼笌澧欏鎺ヨЕ鏃堕棿涓0.2s锛屾眰鍔犻熷害 2鐗╀綋娌夸竴鏉$洿绾胯繍鍔紝鍦╰鏃堕棿鍐呴氳繃鐨勮矾绋...
绛旓細鏁呮湰棰樼瓟妗堜负锛0.643m/s2锛
绛旓細鍥犳鍔犻熷害搴斿綋鏄 a=(0.3-0.1)/2.9 绾=0.069 m/s2 銆(2).鏍规嵁楂樹腑鐗╃悊瀛绠鍗曞叕寮忕畻鍑 閬厜鏉垮垰鍒氶伄浣忕涓涓厜鐢甸棬鐨勭灛鏃堕熷害澶у皬V1^=0.1-0.069*0.15=0.09 m/s. 閬厜鏉垮垰鍒氶伄浣忕浜屼釜鍏夌數闂ㄧ殑鐬椂閫熷害澶у皬V2^=0.3-0.069*0.05=0.297 m/s.鍒欒窛绂籜=锛0.297鐨勫钩鏂-0.09鐨...
绛旓細A.Vm鍙兘鏄2v锛屼笌a1 锛宎2澶у皬鏃犲叧 鍥犱负A銆丅闂磋窛绂讳负S锛屽垯S=Vt 鐗╀綋浠嶢鐐圭敱闈欐鍑哄彂锛屽厛鍖鍔犻熺洿绾杩愬姩锛岋紙鍔犻熷害涓篴1)鍒版煇涓閫熷害Vm鏃讹紝S1=Vm*t1/2 鐒跺悗绔嬪嵆鍋氬寑鍑忛熺洿绾胯繍鍔紝锛堝姞閫熷害澶у皬涓篴2)鑷矪鐐规椂閫熷害鎭板ソ鍑忎负0锛孲2=Vm*t2/2 S=S1+S2=Vm(t1+t2)/2=Vm*t/2 浠t=Vm*t/2...
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绛旓細瑙o細锛1锛夎杩愬姩鍛樹笅钀介珮搴︿负h鐨勬椂鍊欙紝鎵撳紑闄嶈惤浼炪傚垯杩愬姩鍛樺寑鍑忛熶笅钀界殑楂樺害H=224-h锛屾鏃堕熷害涓簐锛岃姹傝惤鍦伴熷害灏忎簬5m/s锛屽垯锛氫緷棰樻剰鍙垪寮忥細224-h=锛坴^2-25)/锛12.5*2锛夆︹︹憼 v=2hg鈥︹︹憽 鈶犮佲憽鑱旂珛锛岃В寰梙=125m (2)鐏溅蹇呴』鍦ㄨ繘鍏ュぇ妗ュ墠鎶婇熷害鍑忓埌10m/s锛岃繖鏈熼棿闇瑕佺殑鏃堕棿t1...
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绛旓細渚濋鎰忔湁锛氱1绉掑唴鐨勪綅绉伙紝v1 = aT =2 m/s 绗2绉掑唴鐨勪綅绉伙紝v2 = v1 =2 m/s 绗3绉掑唴鐨勪綅绉伙紝v3 = v2 + aT =4 m/s 浠ユ绫绘帹锛岀n绉掑唴鐨勪綅绉 鎵浠ワ紝鍥犱负锛屾墍浠ユ湁锛氳В寰梟=15锛坰锛夊嵆缁忚繃15绉掞紝姝ょ墿浣撳畬鎴120m鐨勪綅绉汇傝В娉曚簩锛氾紙鍥捐薄娉曪級鐗╀綋鍙楁媺鍔涗綔鐢ㄦ椂鐨勫姞閫熷害锛歛=F/m=2m...
绛旓細1)涓嬭惤鎬绘椂闂翠负 T=Vt/g H=(1/2)rT^2 (H/2)=(1/2)gt^2 涓嬭惤涓鍗婇珮搴︽墍闇鏃堕棿涓 t=T/(鏍瑰彿2)=0.707T=0.707(Vt/g)涓嬭惤鍚庝竴鍗婇珮搴︽墍闇鏃堕棿涓 t'=T-t=T[1-1/(鏍瑰彿2)]=0.293(Vt/g)2)骞冲潎閫熷害=鏃堕棿涓偣鐬椂閫熷害 璁句笅钀芥绘椂闂翠负t (t-0.5)s鏃剁灛鏃堕熷害V=鏈鍚1s骞冲潎閫熷害=...