锟斤拷锟斤拷tmin=锟斤拷=1600锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷a1=1.6m/s2,a2=6.4m/s2.锟缴�锟绞斤拷锟斤拷vm=64m/s锟斤拷锟斤拷tmin=.锟斤拷锟斤拷虝r锟絞锟斤拷50s.

锟斤拷锟斤拷锟斤拷锟斤拷探锟斤拷锟斤拷锟斤拷锟絵要锟斤拷锟斤拷锟斤拷摩锟斤拷車锟斤拷锟絓锟斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絁锟絉锟斤拷锟斤拷锟斤拷锟剿勶拷變锟劫讹拷直锟斤拷锟酵勶拷锟斤拷直锟斤拷锟絓锟斤拷锟斤拷锟絓锟斤拷锟絕锟斤拷锟絕锟斤拷锟絪锟斤拷锟斤拷锟斤拷锟斤拷位锟狡圖锟斤拷直锟絕锟截斤拷锟侥︼拷锟杰囷拷锟斤拷\锟斤拷锟介景锟斤拷锟斤拷锟节碉拷2锟斤拷锟斤拷锟斤拷直锟絕锟斤拷效锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟节碉拷锟斤拷锟斤拷锟皆筹拷锟劫讹拷2V0锟絈直锟较掞拷一锟斤拷锟絯A锟斤拷锟斤拷锟斤拷锟皆筹拷锟斤拷V0同锟斤拷锟絚锟絈直锟较掞拷锟斤拷一锟斤拷锟絯B锟斤拷锟斤拷要使锟斤拷锟斤拷锟絯锟斤拷锟节匡拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟侥時锟絞锟絞锟斤拷锟斤拷須滿锟斤拷什么锟絣锟斤拷锟斤拷锟斤拷锟斤拷計锟秸氾拷锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟界按通锟斤拷锟斤拷r锟斤拷锟斤拷锟斤拷锟斤拷(j锟斤拷)锟絵锟斤拷锟斤拷锟絓锟接學知锟絉锟叫凤拷锟斤拷锟斤拷锟�锟斤拷锟紷锟角憋拷锟絕锟介煩锟斤拷锟斤拷锟斤拷Q锟絈思路锟斤拷锟斤拷锟斤拷(j锟斤拷)s=V0t-gt2/2锟斤拷s-t锟紻锟襟，則锟斤拷使锟斤拷锟絵锟絕锟教达拷蠛喕锟�锟斤拷锟斤拷D10锟斤拷示锟斤拷锟紷然锟斤拷锟缴條锟紻锟斤拷锟斤拷锟洁交锟絚锟斤拷示A锟斤拷B锟斤拷锟斤拷锟絩锟斤拷锟斤拷锟絭锟斤拷锟剿岋拷锟斤拷位锟斤拷SA=SB锟斤拷锟缴圖10锟斤拷直锟接匡拷锟斤拷Δt锟組锟斤拷锟絇系式锟絩锟斤拷B锟斤拷锟节匡拷锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絰锟絖锟斤拷穴锟斤拷直锟斤拷前锟組锟斤拷锟斤拷锟斤拷锟劫讹拷锟絚锟斤拷锟斤拷穴锟侥撅拷锟絰锟缴凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟組锟斤拷锟絰锟斤拷穴锟斤拷锟絰锟斤拷s1锟侥硷拷處锟絩锟劫度烇拷v1锟斤拷锟斤拷

锟斤拷锟�锟斤拷锟�1锟斤拷锟斤拷锟斤拷锟斤拷锟組锟斤拷锟絚锟絰穴锟斤拷锟絰锟斤拷s2锟斤拷s2锟斤拷s1锟斤拷锟斤拷锟斤拷處锟絩锟斤拷锟劫讹拷锟斤拷

锟斤拷锟�锟斤拷锟�2锟斤拷锟侥硷拷處锟斤拷锟斤拷處锟斤拷锟矫的時锟絞锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷(j锟斤拷)锟絵锟解，锟斤拷锟斤拷锟斤拷锟組锟斤拷锟劫讹拷锟絚锟斤拷锟斤拷锟斤拷穴锟侥撅拷锟絰锟缴凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫v·s锟斤拷k(锟斤拷锟斤拷)

锟斤拷锟斤拷取s锟斤拷v锟斤拷锟斤拷锟斤拷1/v锟斤拷M锟斤拷锟剿ｏ拷锟斤拷锟斤拷s—1/v锟侥圖锟斤拷锟斤拷锟斤拷D1—6锟斤拷示锟斤拷

锟斤拷锟斤拷锟斤拷v1s1锟斤拷v2s2锟斤拷k锟酵圖锟斤拷锟斤拷锟絭2锟酵時锟絞t锟斤拷

锟斤拷锟斤拷锟解：锟斤拷1锟斤拷锟斤拷v1s1锟斤拷v2s2锟斤拷k锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷M锟斤拷s2處锟斤拷锟劫度烇拷

锟斤拷锟�锟斤拷锟�2锟斤拷s—1/v锟紻锟斤拷锟絚锟斤拷锟斤拷锟絊锟斤拷锟斤拷锟斤拷e值锟斤拷锟斤拷锟斤拷r锟絞t锟斤拷锟絫锟斤拷锟斤拷募锟教庯拷锟斤拷M锟斤拷锟斤拷處锟斤拷锟矫時锟絞锟斤拷锟节圖1—1—6锟叫�锟斤拷锟叫憋拷锟斤拷锟斤拷锟斤拷锟斤拷锟絜值锟斤拷锟絫

锟斤拷锟斤拷锟斤拷锟�

锟斤拷锟斤拷锟斤拷锟斤拷一锟叫伙拷車锟斤拷平直軌锟斤拷锟斤拷A處锟絓锟接碉拷B處锟斤拷AB锟斤拷锟斤拷锟絪锟斤拷锟斤拷A處锟斤拷锟給止锟斤拷锟絣(f锟斤拷)锟斤拷锟皆硷拷锟劫讹拷a1锟斤拷锟斤拷锟斤拷锟斤拷\锟接ｏ拷锟絓锟接碉拷途锟斤拷某處C锟絩锟斤拷锟皆硷拷锟劫度达拷小锟斤拷a2锟斤拷锟斤拷p锟斤拷锟絓锟接ｏ拷锟斤拷B處锟絩恰锟斤拷锟給止锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷1锟斤拷锟斤拷車锟絓锟接的匡拷锟絩锟絞锟斤拷

锟斤拷锟�锟斤拷锟�2锟斤拷C處锟絚A處锟侥撅拷锟絰锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷車锟斤拷A锟絓锟接碉拷B锟斤拷v—t锟紻锟斤拷锟斤拷D1—7锟斤拷示锟斤拷锟缴圖锟斤拷锟斤拷锟斤拷锟斤拷t1锟斤拷t2锟斤拷t锟斤拷C處锟斤拷A處锟侥撅拷锟絰锟斤拷

锟斤拷锟斤拷锟解：锟斤拷1锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷式聯(li锟斤拷n)锟斤拷锟斤拷r锟絞

锟斤拷锟�锟斤拷锟�2锟斤拷锟斤拷前锟斤拷锟斤拷锟斤拷模锟�

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷某一锟斤拷锟斤拷锟斤拷锟斤拷變锟斤拷直锟斤拷锟絓锟斤拷锟斤拷锟斤拷t锟斤拷s锟斤拷锟斤拷通锟絕锟斤拷路锟教烇拷s锟斤拷锟斤拷锟斤拷處锟斤拷锟劫度烇拷v1锟斤拷锟斤拷锟斤拷锟絞锟絩锟教碉拷锟劫度烇拷v2锟斤拷锟絫v1锟斤拷v2锟斤拷锟絇系锟斤拷锟角ｏ拷锟斤拷锟斤拷

锟斤拷锟斤拷A锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷锟街憋拷锟斤拷\锟接時锟斤拷vl锟斤拷v2

锟斤拷锟斤拷B锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷p锟斤拷直锟斤拷锟絓锟接時锟斤拷vl锟斤拷v2

锟斤拷锟斤拷C锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷直锟斤拷锟絓锟接時锟斤拷vl锟斤拷v2

锟斤拷锟斤拷D锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷p锟斤拷直锟斤拷锟絓锟接時锟斤拷vl锟斤拷v2

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷锟街憋拷锟斤拷\锟接碉拷v一t锟紻锟斤拷锟斤拷D1—9锟斤拷示锟斤拷處锟斤拷锟劫讹拷v1锟絚锟絩锟斤拷锟劫讹拷v2锟斤拷锟斤拷^锟斤拷vl锟斤拷v2锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷p锟斤拷锟絓锟接時锟斤拷v一t锟紻锟斤拷锟斤拷D1—10锟斤拷示锟斤拷锟缴圖锟斤拷锟街�锟斤拷處锟斤拷锟劫讹拷v1锟斤拷锟斤拷锟斤拷锟絞锟絩锟教碉拷锟劫讹拷v2锟斤拷锟斤拷vl锟斤拷v2锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷知锟絰锟紸锟斤拷B锟斤拷锟斤拷锟斤拷锟絖锟侥ｏ拷

锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷直锟斤拷锟絓锟接時锟斤拷锟斤拷v一t锟紻锟斤拷锟斤拷D1—11锟斤拷示锟斤拷锟缴圖锟斤拷锟街�锟斤拷處锟斤拷锟劫讹拷v1锟絚锟絩锟教碉拷锟劫讹拷v2锟斤拷小锟斤拷锟�锟斤拷锟斤拷vl锟斤拷v2锟斤拷锟斤拷锟斤拷锟絰锟紺也锟斤拷锟斤拷锟絖锟侥ｏ拷

锟斤拷锟斤拷锟斤拷锟斤拷}锟侥得歸锟絳锟斤拷

锟斤拷锟斤拷锟斤拷1锟斤拷锟斤拷锟絵锟解法锟斤拷锟斤拷锟斤拷锟矫旓拷(sh锟斤拷)锟絎知锟絉锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絕v1锟斤拷v2锟侥达拷锟�锟斤拷锟�

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絆锟斤拷锟絯锟斤拷锟劫度烇拷v0锟斤拷末锟劫度烇拷vt锟斤拷锟斤拷锟斤拷(j锟斤拷)锟斤拷式锟斤拷

锟斤拷锟斤拷锟斤拷t锟斤拷0锟斤拷t(s)

锟斤拷锟斤拷锟斤拷t锟斤拷0锟斤拷

锟斤拷锟斤拷锟絫锟斤拷處锟斤拷锟劫度达拷小锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷(j锟斤拷)锟斤拷變锟斤拷直锟斤拷锟絓锟接碉拷锟斤拷锟絴锟斤拷锟斤拷锟斤拷變锟斤拷直锟斤拷锟絓锟接碉拷锟斤拷锟絯锟斤拷某锟轿時锟絞锟饺碉拷平锟斤拷锟劫度碉拷锟斤拷锟紷锟轿時锟絞锟斤拷锟斤拷锟絞锟絩锟教碉拷瞬锟絩锟劫讹拷锟斤拷锟絫

锟斤拷锟斤拷≥0

锟斤拷锟斤拷∴≥

锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟轿凤拷锟斤拷锟街憋拷锟斤拷\锟斤拷锟斤拷v1锟斤拷v2锟斤拷锟斤拷锟斤拷值锟斤拷锟斤拷锟斤拷v1≥v2

锟斤拷锟斤拷锟斤拷锟斤拷x锟紸锟斤拷B锟斤拷锟斤拷锟絖锟侥ｏ拷

锟斤拷锟�锟斤拷锟�2锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟角诧拷锟斤拷鹊锟�

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絴锟斤拷2008锟矫革拷锟斤拷锟斤拷一锟斤拷锟絳锟叫ｏ拷某車隊忥拷同一锟斤拷锟絚锟饺猴拷锟斤拷o止锟絖锟斤拷n锟絭锟斤拷車锟斤拷锟斤拷平直锟侥癸拷路锟斤拷锟斤拷一直锟斤拷锟斤拷锟�锟斤拷锟斤拷車锟斤拷锟斤拷锟斤拷锟斤拷锟劫度烇拷a锟侥勶拷锟斤拷锟街憋拷锟斤拷\锟斤拷锟斤拷锟絖锟斤拷锟劫讹拷v锟斤拷锟斤拷锟斤拷锟斤拷直锟斤拷锟絓锟斤拷锟斤拷锟斤拷車锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷車锟斤拷锟絰锟斤拷锟斤拷s锟斤拷锟絫锟斤拷锟斤拷锟斤拷車锟斤拷锟接的時锟絞锟絞锟斤拷锟介（D锟斤拷

锟斤拷锟斤拷A锟斤拷B锟斤拷C锟斤拷D锟斤拷

锟斤拷锟斤拷追锟斤拷锟絚锟斤拷锟斤拷锟斤拷锟絵

锟斤拷锟斤拷锟斤拷锟絯锟斤拷同一直锟斤拷锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟斤拷锟芥及追锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟阶诧拷葐锟斤拷}锟斤拷

锟斤拷锟斤拷追锟酵憋拷追锟侥冿拷锟斤拷锟絯锟斤拷锟劫讹拷锟斤拷龋锟酵�锟斤拷锟絓锟接ｏ拷锟斤拷锟杰凤拷追锟较硷拷锟斤拷锟斤拷锟斤拷锟斤拷袠O值锟斤拷锟絉锟斤拷l锟斤拷

锟斤拷锟斤拷锟斤拷一類ｏ拷锟劫度达拷锟竭減锟斤拷追锟劫讹拷小锟竭勶拷锟斤拷

锟斤拷锟�锟斤拷佼锟斤拷锟斤拷锟斤拷俣锟斤拷锟饺時锟斤拷锟斤拷追锟斤拷位锟斤拷锟斤拷小锟节憋拷追锟斤拷位锟斤拷锟斤拷锟絫锟斤拷锟絟追锟斤拷锟较ｏ拷锟剿時锟斤拷锟斤拷之锟絞锟斤拷锟斤拷小锟斤拷锟絰锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷俣锟斤拷锟饺時位锟斤拷也锟斤拷锟�锟斤拷锟絫恰锟斤拷追锟较ｏ拷也锟角冿拷锟竭憋拷锟斤拷锟斤拷撞锟斤拷锟絉锟斤拷l锟斤拷

锟斤拷锟�锟斤拷锟斤拷锟斤拷锟斤拷位锟斤拷锟斤拷葧r锟斤拷追锟斤拷锟劫讹拷锟皆达拷锟节憋拷追锟竭碉拷锟劫讹拷锟斤拷锟絫锟斤拷追锟斤拷還锟斤拷一锟斤拷追锟斤拷追锟竭的機锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷一锟斤拷貨車锟斤拷28.8km/h(8m/s)锟斤拷锟劫讹拷锟斤拷平直锟紽路锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟斤拷锟絳锟斤拷失锟絗锟斤拷锟节猴拷锟斤拷600m處锟斤拷一锟叫匡拷車锟斤拷72km/h(20m/s)锟斤拷锟劫讹拷锟斤拷锟斤拷锟斤拷锟斤拷锟�锟斤拷锟杰囁撅拷C锟絣(f锟斤拷)锟絏锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟狡勶拷锟斤拷锟斤拷锟斤拷锟斤拷車要锟斤拷锟斤拷2000m锟斤拷停止.試锟叫旓拷锟斤拷車锟角凤拷锟斤拷锟斤拷锟�.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷車锟劫讹拷锟斤拷锟角∽凤拷锟角败�锟斤拷锟紷锟斤拷恰锟斤拷锟斤拷锟斤拷锟斤拷锟絉锟斤拷锟斤拷r锟斤拷锟斤拷锟街灰�锟斤拷锟絕锟斤拷車锟斤拷锟劫時锟斤拷位锟斤拷锟絇系锟斤拷锟斤拷锟斤拷锟斤拷锟絖锟角凤拷锟斤拷锟斤拷.

锟斤拷锟斤拷锟斤拷锟杰囷拷p锟斤拷锟絓锟接的硷拷锟劫度达拷小锟介：

锟斤拷锟斤拷锟绞匡拷車锟絰車锟斤拷锟斤拷車锟斤拷锟劫歷锟絩锟斤拷

锟斤拷锟斤拷?

锟斤拷锟斤拷該锟絩锟絞锟饺冿拷車位锟狡分別锟角ｏ拷

锟斤拷锟斤拷?

锟斤拷锟斤拷锟斤拷锟絪锟届＞s貨+s0=1560m,锟绞冿拷車锟斤拷锟絣(f锟斤拷)锟斤拷锟斤拷撞.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷車锟斤拷锟斤拷锟斤拷V1锟斤拷前锟斤拷锟�锟斤拷司锟紺突然锟絣(f锟斤拷)锟紽(xi锟斤拷n)锟斤拷前锟斤拷同一軌锟斤拷锟较撅拷車锟斤拷S處锟斤拷锟斤拷一锟絭锟斤拷車锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷同锟侥凤拷锟斤拷锟斤拷锟絕小锟斤拷锟斤拷锟斤拷V2锟斤拷锟斤拷锟斤拷锟絓锟接ｏ拷锟斤拷锟斤拷司锟紺锟斤拷锟斤拷使車锟斤拷锟斤拷p锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟劫度达拷小锟斤拷a,要使锟斤拷車锟斤拷锟斤拷锟斤拷撞锟斤拷锟斤拷锟絘锟斤拷锟組锟斤拷锟絇式锟斤拷

锟斤拷锟斤拷锟解：锟劫讹拷锟斤拷葧r锟斤拷位锟斤拷也锟斤拷葎t恰锟矫诧拷撞锟斤拷

锟斤拷锟斤拷锟斤拷茫锟�锟斤拷锟絫要锟斤拷

锟斤拷锟斤拷锟节讹拷類ｏ拷锟劫讹拷小锟竭硷拷锟斤拷追锟劫度达拷锟竭勶拷锟斤拷

锟斤拷锟斤拷锟劫�锟斤拷锟斤拷锟斤拷俣锟斤拷锟饺時锟斤拷锟斤拷锟斤拷锟絰锟斤拷

锟斤拷锟斤拷锟节冿拷锟斤拷位锟斤拷锟斤拷葧r锟絫追锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷一锟絭值锟节的撅拷車停锟节癸拷路邊锟斤拷锟斤拷锟斤拷锟絋锟絣(f锟斤拷)锟紽(xi锟斤拷n)锟斤拷锟斤拷锟斤拷邊锟斤拷10m/s锟斤拷锟劫度勶拷锟斤拷锟斤拷锟斤拷貨車锟斤拷锟截筹拷锟絛锟絩锟斤拷锟絈锟斤拷前去追锟絪锟斤拷锟斤拷(j锟斤拷ng)锟絕5.5s锟斤拷車锟絣(f锟斤拷)锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷2.5m/s2锟侥硷拷锟劫讹拷锟斤拷锟斤拷锟斤拷锟斤拷\锟斤拷锟斤拷锟斤拷锟斤拷車锟斤拷锟斤拷锟斤拷俣缺锟巾毧锟斤拷锟斤拷锟�90km/h锟皆內ｏ拷锟斤拷锟斤拷

锟斤拷锟斤拷(1锟斤拷锟斤拷車锟斤拷追锟絪貨車锟斤拷锟絕锟斤拷锟叫ｏ拷锟斤拷車锟絞锟斤拷锟斤拷锟斤拷锟絰锟角讹拷锟斤拷锟斤拷

锟斤拷锟斤拷(2锟斤拷锟斤拷車锟絣(f锟斤拷)锟接猴拷要锟斤拷锟絃锟絩锟絞锟斤拷锟斤拷追锟斤拷貨車锟斤拷

锟斤拷锟斤拷锟解：锟斤拷l锟斤拷锟斤拷車锟斤拷追锟絪貨車锟斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷車锟劫讹拷锟斤拷葧r锟斤拷锟斤拷锟斤拷锟侥撅拷锟絰锟斤拷锟�锟斤拷锟絆锟斤拷車锟絣(f锟斤拷)锟接猴拷(j锟斤拷ng)锟絕t1锟絩锟絞锟斤拷車锟斤拷锟劫讹拷锟斤拷龋锟斤拷t锟斤拷

锟斤拷锟斤拷(1锟斤拷)

锟斤拷锟斤拷s貨=(5.5+4)×10m=95m(1锟街ｏ拷

锟斤拷锟斤拷s锟斤拷(1锟斤拷)

锟斤拷锟斤拷锟斤拷锟皆冿拷車锟絞锟斤拷锟斤拷锟斤拷锟絰锟斤拷s=s貨-s锟斤拷=75m锟斤拷1锟街ｏ拷

锟斤拷锟斤拷(2)v0=90km/h=25m/s锟斤拷锟斤拷锟斤拷車锟斤拷锟絖锟斤拷锟斤拷锟斤拷俣葧r锟斤拷锟絓锟接時锟絞锟斤拷锟斤拷l锟街ｏ拷

锟斤拷锟斤拷s貨’=(5.5+10)×10m=155m(1锟街ｏ拷

锟斤拷锟斤拷s锟斤拷’=锟斤拷1锟街ｏ拷

锟斤拷锟斤拷锟斤拷锟絪貨’锟斤拷s锟斤拷’锟斤拷锟绞此時锟斤拷車锟斤拷未锟絪锟斤拷貨車锟斤拷锟揭此時锟缴憋拷锟斤拷锟絰锟斤拷s’=s貨’-s锟斤拷’=30m锟斤拷l锟街ｏ拷

锟斤拷锟斤拷锟斤拷車锟絖锟斤拷锟斤拷锟斤拷俣群锟斤拷锟斤拷锟斤拷锟斤拷\锟斤拷锟斤拷锟絆锟劫斤拷(j锟斤拷ng)锟絕锟斤拷t锟絩锟絞锟斤拷锟絪锟斤拷貨車锟斤拷锟絫锟斤拷

锟斤拷锟斤拷(1锟街ｏ拷

锟斤拷锟斤拷锟斤拷锟皆撅拷車锟絣(f锟斤拷)锟接猴拷耍锟斤拷(j锟斤拷ng)锟絕锟斤拷锟斤拷追锟斤拷貨車锟斤拷(1锟街ｏ拷

锟斤拷锟斤拷锟斤拷锟斤拷摩锟斤拷車锟斤拷锟斤拷锟給止锟絖始锟皆的硷拷锟劫讹拷锟斤拷锟斤拷锟斤拷锟斤拷\锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟劫讹拷25m/s锟斤拷锟斤拷锟絓锟斤拷锟斤拷追锟絪前锟斤拷锟斤拷15m/s锟斤拷锟劫讹拷同锟斤拷锟斤拷锟斤拷锟斤拷目锟杰囷拷锟斤拷锟街�摩锟斤拷車锟絖始锟絓锟接時锟絚锟斤拷車锟侥撅拷锟絰锟斤拷1000m锟斤拷锟絫锟斤拷

锟斤拷锟�锟斤拷锟�1锟斤拷追锟较匡拷車前锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷x锟角讹拷锟斤拷锟斤拷

锟斤拷锟�锟斤拷锟�2锟斤拷摩锟斤拷車锟斤拷(j锟斤拷ng)锟絕锟斤拷锟劫時锟絞锟斤拷锟斤拷追锟较匡拷車锟斤拷

锟斤拷锟�锟斤拷锟�1锟斤拷锟斤拷锟絵锟斤拷锟侥︼拷锟杰囷拷锟斤拷锟斤拷锟絓锟斤拷锟斤拷锟絃锟絩锟絞锟斤拷

锟斤拷锟斤拷位锟狡ｏ拷锟斤拷锟斤拷摩锟斤拷車锟斤拷锟絖锟斤拷锟斤拷俣锟街�前锟絔锟斤拷追锟较匡拷車锟斤拷锟絫追锟较匡拷車前锟斤拷锟斤拷锟劫讹拷锟斤拷锟斤拷锟斤拷g锟斤拷锟斤拷锟�锟斤拷锟絆锟斤拷锟絖始锟斤拷(j锟斤拷ng)锟絕t2锟絩锟絞锟劫讹拷锟斤拷锟�锟斤拷锟斤拷锟斤拷g锟斤拷锟斤拷Sm锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷∴

锟斤拷锟斤拷锟斤拷锟斤拷g锟斤拷

锟斤拷锟斤拷锟斤拷2锟斤拷锟絆锟斤拷锟絖始锟斤拷(j锟斤拷ng)锟絕t锟絩锟絞摩锟斤拷車追锟较匡拷車锟斤拷锟絫锟斤拷

锟斤拷锟斤拷锟斤拷锟絫=120s

锟斤拷锟斤拷锟斤拷锟斤拷類ｏ拷锟斤拷锟斤拷追前锟斤拷锟斤拷

锟斤拷锟斤拷锟劫讹拷锟斤拷葧r锟斤拷锟絔追锟斤拷锟斤拷锟絫锟斤拷锟絟追锟斤拷锟较★拷

锟斤拷锟斤拷锟斤拷位锟斤拷锟斤拷葧r追锟斤拷锟劫度达拷锟节憋拷追锟斤拷锟劫讹拷锟斤拷锟絫锟斤拷锟絕锟斤拷锟斤拷锟斤拷追锟斤拷還锟斤拷锟劫次筹拷锟絕追锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷車锟斤拷锟給止锟絖始锟斤拷a=1m/s2锟侥硷拷锟劫讹拷锟斤拷锟斤拷锟斤拷锟街憋拷锟斤拷\锟斤拷锟斤拷車锟斤拷锟斤拷锟絪=25m處锟斤拷锟斤拷锟斤拷υ=6m/s锟斤拷锟劫度勶拷锟斤拷锟絓锟接讹拷追車锟斤拷锟斤拷锟斤拷锟斤拷锟杰凤拷追锟斤拷車锟斤拷锟斤拷锟剿诧拷锟斤拷追锟斤拷車.

锟斤拷锟斤拷锟斤拷锟斤拷锟阶★拷锟揭冿拷锟絴锟絚同锟絩锟絖始锟节彼达拷平锟斤拷锟揭匡拷锟斤拷锟侥冿拷水平軌锟斤拷锟斤拷同锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟斤拷前锟斤拷锟斤拷锟节猴拷锟斤拷锟斤拷锟絪锟斤拷锟阶筹拷锟劫度烇拷锟斤拷锟斤拷锟斤拷锟劫度烇拷a锟斤拷锟斤拷锟斤拷锟斤拷锟街憋拷锟斤拷\锟斤拷锟斤拷锟斤拷锟斤拷锟劫讹拷v0锟斤拷锟斤拷锟斤拷锟絓锟接ｏ拷锟絇锟节冿拷锟絴锟絚锟斤拷锟斤拷锟斤拷前锟斤拷锟絓锟斤拷锟斤拷

锟斤拷锟斤拷某同锟絎锟斤拷锟斤拷锟铰凤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟絆锟斤拷锟絴锟絚锟斤拷锟斤拷前锟斤拷锟斤拷锟斤拷之锟絞锟侥撅拷锟絰锟斤拷锟絪锟斤拷锟絫锟斤拷锟斤拷锟絩锟斤拷锟斤拷锟絴锟絚锟絞锟斤拷锟絰锟斤拷s锟斤拷锟斤拷小值锟斤拷也锟斤拷锟角冿拷锟絴锟絚锟劫讹拷锟斤拷葧r锟斤拷锟斤拷锟絴锟絚之锟絞锟斤拷锟絰锟斤拷锟�锟斤拷

锟斤拷锟斤拷锟斤拷锟絏锟斤拷锟斤拷锟侥凤拷锟斤拷锟角凤拷锟斤拷锟絖锟斤拷锟斤拷锟斤拷J锟斤拷锟斤拷锟斤拷锟絖锟斤拷锟斤拷請锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟叫★拷锟斤拷x锟斤拷锟斤拷锟斤拷J锟斤拷锟角诧拷锟斤拷锟絖锟斤拷锟斤拷請锟絝锟斤拷锟斤拷锟缴诧拷锟斤拷锟斤拷锟斤拷锟絖锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絖锟斤拷

锟斤拷锟斤拷锟絆锟斤拷锟斤拷锟絯锟劫讹拷锟斤拷葧r恰锟斤拷锟斤拷锟斤拷锟斤拷锟絫

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫锟斤拷锟斤拷锟斤拷之前锟侥撅拷锟絰始锟終锟节減小锟斤拷直锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷小锟斤拷锟絰Δs锟斤拷0锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟紽(xi锟斤拷n)Δs锟斤拷小锟斤拷锟斤拷r锟斤拷

锟斤拷锟斤拷锟斤拷s>锟絩锟斤拷锟斤拷锟絚锟揭诧拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絴锟絚锟斤拷锟絰锟斤拷锟斤拷锟紽(xi锟斤拷n)锟斤拷變小锟斤拷變锟斤拷锟斤拷锟絩锟斤拷锟斤拷t=锟絩锟斤拷锟斤拷锟絴锟絚之锟絞锟侥撅拷锟絰锟斤拷锟�锟斤拷锟斤拷Δsmin锟斤拷s锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷}:注锟斤拷弄锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟絓锟接猴拷锟絈直锟较掞拷锟絓锟接碉拷锟斤拷锟絚

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟絓锟斤拷锟角筹拷锟劫度烇拷锟斤拷锟斤拷锟斤拷锟劫度烇拷g锟侥勶拷锟斤拷锟街憋拷锟斤拷\锟斤拷

锟斤拷锟斤拷锟絈直锟较掞拷锟絓锟斤拷锟角勶拷變锟斤拷直锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟紸锟轿烇拷锟絧锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟斤拷锟紸锟轿烇拷锟斤拷锟斤拷锟斤拷锟絯锟絓锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟斤拷

锟斤拷锟斤拷1.锟斤拷锟斤拷锟斤拷锟铰斤拷锟斤拷锟斤拷锟斤拷锟皆�處锟斤拷锟侥兩傦拷锟絕锟教伙拷锟斤拷锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟叫岋拷锟絈锟斤拷锟斤拷锟斤拷锟斤拷锟叫結論锟斤拷

锟斤拷锟斤拷(1)锟劫度岋拷锟絈锟斤拷锟斤拷锟斤拷锟斤拷锟铰斤拷锟絕锟斤拷锟斤拷锟絴锟絚锟斤拷(j锟斤拷ng)锟絕同一位锟矫碉拷锟劫度达拷小锟斤拷锟�锟斤拷锟斤拷锟斤拷锟洁反锟斤拷

锟斤拷锟斤拷锟斤拷2锟斤拷锟絩锟絞锟斤拷锟絈锟斤拷锟斤拷锟斤拷锟斤拷锟铰斤拷锟斤拷(j锟斤拷ng)锟絭锟侥時锟絞锟斤拷锟�锟斤拷

锟斤拷锟斤拷2.锟絈直锟较掞拷锟絓锟接碉拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷1锟斤拷锟斤拷锟斤拷锟斤拷锟竭度ｏ拷Sm=.(2)锟斤拷锟斤拷锟斤拷锟竭度和忥拷锟斤拷锟竭讹拷锟絚锟斤拷锟戒到锟斤拷锟斤拷锟絚锟斤拷锟絕锟斤拷锟斤拷锟斤拷(j锟斤拷ng)锟絭锟侥時锟絞锟斤拷.

锟斤拷锟斤拷锟斤拷锟斤拷A锟斤拷锟皆撅拷锟斤拷锟斤拷h處锟絖始锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷同锟絩B锟斤拷锟皆筹拷锟劫讹拷v0锟斤拷锟斤拷A锟斤拷锟絈直锟较掞拷锟斤拷锟秸氾拷锟斤拷锟斤拷锟斤拷計.锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷1锟斤拷要使锟斤拷锟斤拷锟斤拷B锟斤拷锟斤拷锟斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫v0锟斤拷锟組锟斤拷什么锟絣锟斤拷锟斤拷?

锟斤拷锟�锟斤拷锟�2锟斤拷要使锟斤拷锟斤拷锟斤拷B锟斤拷锟铰斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫v0锟斤拷锟組锟斤拷什么锟絣锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絩位锟斤拷之锟酵碉拷锟斤拷h.锟斤拷锟斤拷?锟斤拷锟皆ｏ拷

锟斤拷锟斤拷锟斤拷B锟斤拷锟斤拷锟斤拷锟侥時锟絞锟斤拷锟斤拷B锟斤拷锟节匡拷锟斤拷锟絓锟接的匡拷锟絩锟絞锟斤拷?

锟斤拷锟斤拷(1)锟斤拷使锟斤拷锟斤拷锟斤拷B锟斤拷锟斤拷锟斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫锟斤拷

锟斤拷锟斤拷t锟斤拷t1,锟斤拷,锟斤拷锟斤拷

锟斤拷锟斤拷(2)锟斤拷使锟斤拷锟斤拷锟斤拷B锟斤拷锟铰斤拷锟絕锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫锟叫ｏ拷?

锟斤拷锟斤拷t1锟斤拷t锟斤拷t2

锟斤拷锟斤拷锟斤拷:

锟斤拷锟斤拷锟斤拷锟皆ｏ拷?

锟斤拷锟斤拷锟斤拷:锟斤拷1锟斤拷(2)

锟斤拷锟斤拷锟斤拷锟斤拷锟絴锟絚锟斤拷锟絈直锟较掞拷锟絓锟接ｏ拷锟缴次斤拷(j锟斤拷ng)锟絕A锟絚锟侥時锟絞锟絞锟斤拷锟斤拷t1锟斤拷锟缴次斤拷(j锟斤拷ng)锟絕A锟絚锟斤拷锟较凤拷锟斤拷B锟絚锟侥時锟絞锟絞锟斤拷锟斤拷t2锟斤拷锟絫A锟絚B锟絞锟斤拷锟絰锟斤拷__________.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絈直锟较掞拷锟絓锟接碉拷“锟斤拷锟絈锟斤拷锟斤拷”锟缴給锟斤拷锟斤拷锟轿的斤拷锟�

锟斤拷锟斤拷锟解：锟斤拷锟絈直锟较掞拷锟絓锟接碉拷“锟斤拷锟絈”锟斤拷锟斤拷锟斤拷知锟斤拷锟絴锟絚锟斤拷锟斤拷锟斤拷c锟斤拷锟斤拷锟斤拷锟斤拷A锟斤拷B锟斤拷锟絚锟斤拷锟斤拷(j锟斤拷ng)锟絭锟絩锟絞锟截烇拷t1锟斤拷t2锟斤拷锟斤拷锟斤拷直锟接可碉拷

锟斤拷锟斤拷=g(t1)2锟斤拷g(t2)2=g(锟斤拷)

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟絈直锟较掞拷锟絓锟斤拷锟斤拷取g=10m/s2.锟斤拷锟斤拷1s锟斤拷位锟狡达拷小恰锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟竭度的憋拷锟斤拷锟斤拷锟斤拷锟絯锟侥筹拷锟劫讹拷.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷同锟絎锟斤拷锟斤拷(j锟斤拷)锟絵锟斤拷锟缴伙拷锟斤拷規(gu锟斤拷)锟斤拷锟叫筹拷锟斤拷知t锟斤拷gt2=·

锟斤拷锟斤拷锟侥凤拷锟教侊拷锟斤拷猓�锟斤拷锟絴锟较凤拷锟斤拷锟斤拷说锟絫锟斤拷gt2锟斤拷锟斤拷锟斤拷锟絵目锟斤拷锟斤拷锟絝锟斤拷“位锟狡达拷小”锟斤拷锟斤拷只锟斤拷“位锟斤拷”锟斤拷锟斤拷锟斤拷锟斤拷锟筋不锟藉導锟斤拷锟斤拷锟絜锟絗锟侥產(ch锟斤拷n)锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟斤拷锟絵锟斤拷锟斤拷=·锟斤拷

锟斤拷锟斤拷锟組锟斤拷锟斤拷锟�=30m/s锟斤拷=6m/s锟斤拷=4.45m/s

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷D锟斤拷示锟斤拷锟絃锟斤拷1m锟侥桿锟矫短撅拷锟斤拷锟斤拷21m锟斤拷處锟斤拷锟节硷拷锟洁線锟斤拷同锟絩锟斤拷锟斤拷锟斤拷一小锟斤拷锟斤拷υ0=20m/s锟侥筹拷锟劫讹拷锟絈直锟斤拷锟较掞拷锟斤拷锟斤拷取g=10m/s2锟斤拷锟絫锟斤拷(j锟斤拷ng)锟絩锟絞t=______s锟斤拷小锟斤拷锟絚锟経锟斤拷锟铰端等革拷锟斤拷锟劫斤拷(j锟斤拷ng)锟絩锟絞锟斤拷t=____________s锟斤拷小锟斤拷锟絚锟経锟斤拷锟较端等革拷.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟皆碉拷锟斤拷閰�锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷w锟斤拷锟絓锟斤拷锟絇系锟斤拷锟斤拷锟杰忥拷锟絪锟斤拷锟斤拷锟斤拷锟絈一锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�.

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟絈直锟较掞拷锟絓锟接ｏ拷取g=10m/s2锟斤拷锟斤拷锟斤拷锟絓锟接碉拷前5s锟斤拷通锟絕锟斤拷路锟教烇拷65m锟斤拷锟絫锟斤拷锟斤拷俣却锟叫★拷锟斤拷転锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷谐锟斤拷锟斤拷锟絪=υ0t锟斤拷gt2锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絇锟斤拷(sh锟斤拷)锟斤拷(j锟斤拷)s=65m锟斤拷t=5s锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�

锟斤拷锟斤拷υ0=38m/s锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟紷一锟斤拷锟斤拷锟斤拷e锟絗锟斤拷锟斤拷锟斤拷锟斤拷锟�5s锟饺ｏ拷锟斤拷锟絈直锟较掞拷锟絓锟接碉拷锟斤拷锟絯锟斤拷锟絓锟斤拷锟斤拷r锟斤拷锟斤拷锟铰兩種锟斤拷锟斤拷锟皆ｏ拷

锟斤拷锟�锟斤拷锟角�5s锟斤拷锟斤拷锟絯锟斤拷未锟斤拷锟絖锟斤拷锟斤拷c.锟斤拷锟紷锟絅锟斤拷r锟铰ｏ拷锟斤拷锟斤拷锟斤拷锟斤拷锟叫碉拷s锟絖锟斤拷锟斤拷锟斤拷锟絁锟斤拷锟斤拷前5s锟饺碉拷路锟斤拷锟斤拷锟斤拷锟剿時υ0锟斤拷該锟杰碉拷υ0≥50m/s锟斤拷锟狡約锟斤拷锟斤拷锟斤拷锟斤拷锟矫的結論锟斤拷锟节诧拷锟組锟斤拷锟紷一锟狡約锟絣锟斤拷锟斤拷锟斤拷锟杰筹拷锟斤拷.

锟斤拷锟�锟斤拷锟角�5s锟斤拷锟斤拷锟絯锟窖斤拷(j锟斤拷ng)處锟斤拷锟斤拷锟斤拷锟紸锟轿ｏ拷锟斤拷锟紷锟絅锟斤拷r锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟叫碉拷s只锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷w锟斤拷前5s锟饺碉拷位锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷前5s锟饺碉拷路锟斤拷d要小锟斤拷锟斤拷锟剿時锟斤拷锟斤拷

锟斤拷锟斤拷锟解：锟斤拷锟絓锟斤拷規(gu锟斤拷)锟缴可碉拷d=+g(t锟斤拷)2锟斤拷

锟斤拷锟斤拷锟节此伙拷锟紸锟较帮拷锟斤拷锟絇锟斤拷(sh锟斤拷)锟斤拷(j锟斤拷)d=65m锟斤拷t=5s锟斤拷锟斤拷锟斤拷锟斤拷υ0=20m/s锟斤拷υ0=30m/s锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷一锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�锟斤拷锟节碉拷锟絖锟斤拷锟斤拷前锟斤拷锟�1s锟斤拷通锟絕锟斤拷位锟斤拷锟斤拷锟斤拷锟斤拷位锟狡碉拷9/25锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷g取10m/s2锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟絆锟斤拷锟絯锟斤拷锟戒總锟絩锟絞锟斤拷t锟斤拷锟斤拷锟竭烇拷h锟斤拷锟絫锟斤拷,

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟教斤拷茫锟絫=5s,锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷D9锟斤拷示锟斤拷锟揭掞拷锟街憋拷UAB锟絃锟斤拷L1锟斤拷锟斤拷锟斤拷锟斤拷L2處锟斤拷锟斤拷一锟絃锟斤拷L3锟侥無锟阶圓筒CD锟斤拷锟紧將懸撅拷锟斤拷锟斤拷锟斤拷锟絫直锟経锟斤拷锟絕锟紸筒锟斤拷锟矫的時锟絞锟斤拷锟斤拷锟�锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：直锟経锟斤拷锟絕锟紸筒锟斤拷锟矫的時锟絞锟角從桿B锟絚锟戒到筒C锟斤拷锟絖始锟斤拷锟斤拷锟経锟斤拷A锟斤拷锟戒到D锟剿結锟斤拷锟斤拷

锟斤拷锟斤拷锟絆锟経B锟戒到C锟斤拷锟斤拷锟矫的時锟絞锟斤拷t1,锟経A锟斤拷锟戒到D锟斤拷锟斤拷锟矫的時锟絞锟斤拷t2,锟斤拷位锟狡癸拷式锟矫ｏ拷

锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷10m/s锟斤拷锟劫度勶拷锟斤拷锟絈直锟斤拷锟斤拷锟斤拷锟侥氾拷锟斤拷锟较碉拷锟斤拷一锟斤拷锟斤拷锟絯锟斤拷锟斤拷(j锟斤拷ng)17s锟斤拷锟絖锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷脫锟絰锟斤拷锟斤拷r锟斤拷锟斤拷母叨锟�锟斤拷锟斤拷g=10m/s2锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟缴岋拷锟斤拷锟絯锟斤拷锟絓锟斤拷锟絕锟斤拷視锟斤拷锟阶冿拷锟街憋拷锟斤拷\锟接★拷規(gu锟斤拷)锟斤拷锟斤拷锟铰凤拷锟斤拷锟斤拷锟�锟斤拷锟絫锟斤拷锟絯锟斤拷

锟斤拷锟斤拷锟斤拷锟劫度烇拷V0=锟斤拷10m/s,g=10m/s2

锟斤拷锟斤拷锟絫锟斤拷(j锟斤拷)h=,锟絫锟叫ｏ拷

锟斤拷锟斤拷∴锟斤拷锟絯锟斤拷锟斤拷锟铰時锟絰锟斤拷1275m锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷一锟斤拷水锟絓锟接員锟斤拷锟絰水锟斤拷10m锟竭碉拷平锟絖锟斤拷锟斤拷锟斤拷锟絊锟斤拷锟斤拷锟絜锟絧锟斤拷直锟絯锟絰锟絖锟絖锟芥，锟剿時锟斤拷锟斤拷锟斤拷位锟节忥拷锟街碉拷锟絖全锟絃锟斤拷锟斤拷锟斤拷锟斤拷锟絊锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟�0锟斤拷45m锟絖锟斤拷锟斤拷锟斤拷c锟斤拷锟斤拷水锟絩锟斤拷锟絯锟絈直锟斤拷锟斤拷锟斤拷锟斤拷水锟斤拷锟节达拷锟絕锟斤拷锟斤拷锟絓锟接員水平锟斤拷锟斤拷锟斤拷\锟接猴拷锟皆诧拷計锟斤拷锟斤拷锟斤拷锟絰锟絖锟斤拷锟絖锟斤拷锟斤拷锟絴水锟芥，锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷煽锟斤拷袆锟斤拷锟斤拷臅r锟絞锟斤拷s锟斤拷锟斤拷計锟斤拷r锟斤拷锟斤拷锟皆帮拷锟絓锟接員锟斤拷锟斤拷全锟斤拷锟絴锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟侥碉拷一锟斤拷锟絴锟絚锟斤拷g取10m/s2锟斤拷锟結锟斤拷锟斤拷锟斤拷锟斤拷位锟斤拷(sh锟斤拷)锟街ｏ拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟絆锟絓锟接員锟絊锟斤拷r锟侥筹拷锟劫度烇拷V0锟斤拷锟斤拷锟絆锟斤拷锟较烇拷锟斤拷锟斤拷锟絫锟斤拷V20=2gh锟矫ｏ拷

锟斤拷锟斤拷锟斤拷锟絵锟斤拷锟街�锟斤拷锟絓锟接員锟斤拷全锟絕锟斤拷锟叫匡拷锟絁锟斤拷锟斤拷锟斤拷锟絈直锟较掞拷锟絓锟斤拷锟斤拷锟斤拷位锟狡达拷小锟斤拷10m锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷S=锟斤拷10m.

锟斤拷锟斤拷锟缴得ｏ拷,锟斤拷锟絫=1.7s

锟斤拷锟斤拷锟斤拷锟斤拷}:注锟斤拷弄锟斤拷聯(li锟斤拷n)系锟斤拷锟紿锟斤拷锟絵锟侥凤拷锟斤拷锟斤拷狻�

锟斤拷锟斤拷锟斤拷锟斤拷锟紻14锟斤拷a锟斤拷锟斤拷锟节革拷锟劫癸拷路锟斤拷锟矫筹拷聲锟斤拷锟統锟劫儀锟統锟斤拷車锟劫碉拷示锟斤拷D锟斤拷锟統锟劫儀锟絣(f锟斤拷)锟斤拷锟斤拷锟斤拷锟秸筹拷聲锟斤拷锟絵锟絖锟斤拷號锟斤拷锟斤拷锟斤拷(j锟斤拷)锟絣(f锟斤拷)锟斤拷锟酵斤拷锟秸碉拷锟侥時锟絞锟斤拷锟斤拷锟統锟斤拷锟斤拷車锟斤拷锟劫讹拷锟斤拷锟紻14锟斤拷b锟斤拷锟斤拷锟角測锟劫儀锟絣(f锟斤拷)锟斤拷锟侥筹拷聲锟斤拷锟斤拷號锟斤拷n1锟斤拷n2锟街別锟斤拷锟斤拷锟斤拷車锟斤拷锟斤拷貋锟斤拷锟斤拷锟教�锟斤拷锟絆锟統锟劫儀锟斤拷锟劫掞拷锟借，p1锟斤拷锟斤拷p2之锟絞锟侥時锟絞锟絞锟斤拷Δt锟斤拷1.0s锟斤拷锟斤拷聲锟斤拷锟节空氾拷锟叫傦拷锟斤拷锟斤拷锟劫讹拷锟斤拷V锟斤拷340m./s锟斤拷锟斤拷锟斤拷車锟角勶拷锟斤拷锟斤拷锟斤拷锟斤拷锟絫锟斤拷锟斤拷(j锟斤拷)锟紻14锟斤拷b锟斤拷锟斤拷知锟斤拷锟斤拷車锟节斤拷锟秸碉拷p1锟斤拷锟斤拷p2锟缴傦拷锟斤拷號之锟絞锟侥時锟絞锟斤拷前锟組锟侥撅拷锟絰锟斤拷---m锟斤拷锟斤拷車锟斤拷锟劫讹拷锟斤拷_____________m/s

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟斤拷锟絵锟斤拷锟斤拷x锟紻14锟斤拷b锟斤拷锟襟，無锟斤拷讓锟斤拷锟节达拷锟絏锟斤拷直锟斤拷锟轿成測锟劫儀锟絣(f锟斤拷)锟斤拷徒锟斤拷艹锟铰曪拷锟斤拷约锟斤拷蓚锟斤拷锟铰曪拷锟斤拷趥锟斤拷锟斤拷^锟斤拷锟斤拷锟斤拷值锟絇系锟斤拷锟斤拷锟斤拷锟斤拷锟紻锟斤拷锟斤拷只锟斤拷锟叫硷拷锟截凤拷锟斤拷锟紻14锟斤拷b锟斤拷锟斤拷锟斤拷號锟斤拷要锟截ｏ拷锟斤拷痰锟剿硷拷锟斤拷艜锟斤拷诖锟斤拷X锟斤拷锟轿成測锟劫儀锟斤拷P1锟絩锟教發(f锟斤拷)锟斤拷锟侥筹拷聲锟斤拷锟斤拷锟斤拷(j锟斤拷ng)锟斤拷車锟斤拷锟斤拷锟�(j锟斤拷ng)锟絕t1=0.4S锟斤拷锟秸碉拷锟斤拷號锟斤拷锟斤拷P2锟絩锟教發(f锟斤拷)锟斤拷锟侥筹拷聲锟斤拷锟斤拷锟斤拷(j锟斤拷ng)锟斤拷車锟斤拷锟斤拷锟�(j锟斤拷ng)锟絕t2=0.3S锟斤拷锟秸碉拷锟斤拷號锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷榫帮拷D锟斤拷锟斤拷锟斤拷锟斤拷(j锟斤拷)锟紷些锟斤拷息锟斤拷锟斤拷锟阶給锟斤拷锟斤拷锟铰斤拷锟�

锟斤拷锟斤拷锟斤拷車锟节斤拷锟秸碉拷p1锟斤拷锟斤拷p2锟缴傦拷锟斤拷號之锟絞锟侥時锟絞锟斤拷前锟組锟侥撅拷锟絰锟斤拷:

锟斤拷锟斤拷---S=V锟斤拷t1-t2锟斤拷/2=17m锟斤拷锟斤拷車通锟絕锟紷一位锟斤拷锟斤拷锟矫的時锟絞t=Δt-锟斤拷t1-t2锟斤拷/2=0.95S.锟斤拷锟斤拷锟斤拷車锟斤拷锟劫讹拷锟斤拷.

锟斤拷锟斤拷锟斤拷锟斤拷锟絳锟斤拷(ji锟斤拷)水锟斤拷锟絕锟斤拷讓水一锟轿碉拷锟斤拷锟斤拷锟斤拷锟斤拷锟铰凤拷锟斤拷一锟絇锟斤拷锟斤拷锟絳锟斤拷(ji锟斤拷)锟絇锟接高讹拷锟斤拷使一锟斤拷水锟斤拷锟斤拷锟斤拷锟絇锟接時锟斤拷恰锟斤拷锟斤拷一锟斤拷水锟斤拷锟絖始锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷還锟斤拷一锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟叫碉拷水锟斤拷锟斤拷锟統锟斤拷水锟斤拷锟絕锟斤拷锟絇锟接的撅拷锟絰锟斤拷h锟斤拷锟侥碉拷一锟斤拷锟絖始锟斤拷锟斤拷r計锟絩锟斤拷锟斤拷锟斤拷n锟斤拷水锟斤拷锟斤拷锟节盤锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷去锟絩锟絞t锟斤拷锟絫锟剿時锟节ｏ拷n+1锟斤拷锟斤拷水锟斤拷锟絚锟絇锟接的撅拷锟絰锟斤拷锟斤拷锟�锟斤拷锟斤拷?sh锟斤拷)氐锟斤拷锟斤拷锟斤拷锟斤拷俣葹锟斤拷锟劫�?/p>

锟斤拷锟斤拷锟斤拷锟斤拷锟絚锟解：锟絆锟缴傦拷水锟斤拷锟絞锟侥時锟絞锟斤拷T锟斤拷锟斤拷D15锟斤拷示锟斤拷锟斤拷锟斤拷(j锟斤拷)锟斤拷锟斤拷锟斤拷锟絯锟絓锟斤拷規(gu锟斤拷)锟缴可得ｏ拷

锟斤拷锟斤拷,

锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷茫锟斤拷藭r锟节ｏ拷n+1锟斤拷锟斤拷水锟斤拷锟絚锟絇锟接的撅拷锟絰锟介，锟斤拷?sh锟斤拷)氐锟斤拷锟斤拷锟斤拷锟斤拷俣锟絞=

锟斤拷锟斤拷锟斤拷锟斤拷}:锟斤拷锟絰锟斤拷锟斤拷系

锟斤拷锟斤拷一锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟节诧拷同锟斤拷锟斤拷系锟斤拷锟絓锟斤拷锟斤拷锟絴一锟姐不同锟斤拷通锟絕變锟絈锟斤拷锟斤拷系锟斤拷锟斤拷锟皆岋拷锟斤拷锟絪锟斤拷锟絯锟斤拷锟絓锟接猴拷锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷}:“锟斤拷锟斤拷思锟絊”锟斤拷

锟斤拷锟斤拷锟斤拷锟斤拷锟絕锟斤拷處锟斤拷锟斤拷锟斤拷锟斤拷思锟絊锟斤拷锟斤拷锟角帮拷锟絓锟斤拷锟絕锟教碉拷“末锟斤拷”锟斤拷锟斤拷“锟斤拷锟紹(t锟斤拷i)”锟侥凤拷锟斤拷锟叫撅拷锟斤拷锟絵锟侥凤拷锟斤拷锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟斤拷锟斤拷锟絓锟接匡拷锟缴凤拷锟斤拷臏p锟斤拷锟絓锟斤拷锟斤拷锟斤拷锟絯锟斤拷锟絧锟斤拷锟絓锟接匡拷锟缴凤拷锟斤拷募锟斤拷锟斤拷\锟斤拷處锟斤拷锟斤拷該锟斤拷锟斤拷一锟斤拷锟斤拷锟斤拷末锟斤拷B(t锟斤拷i)锟斤拷知锟斤拷锟斤拷r锟斤拷