𰸺ͽ
𰸡 1. C 8. B 15. BD
2. D 3. C 9. C 10. C 16. BCD
4. C 11. BD
5. B 12. BC
6. C 13. BD
7. A 14. BC
17. 0.400.80
18. ⣺1ɵ
ȼʱļٶ
ȼʱļٶ
2ȼʱλΪʱλΪ
ȼʱλΪ
ȫ̵ƽٶΪ
19. ⣺1֪ǰʱٶȣʸȱֱ˶ٶʱϵУ v=v1-a1t v=v2+a2t
ٶʱУ v1-a1t=v2+a2t
ݿɵt=4s Դʱ׳λҳλƣ
xmax=x-x=48m-24m=24m 2֪׳˶ʱΪ
=48m =24m
5
ڼ׳ͣǰλʱϵУ ʱ㣺ݵã
֮t=8sһֵt=0ȥ Ϊt=8st
ʱΪ8s
𣺣1ڴǰΪ24m 2ڴʱΪ8s 20. ⣺1˶Ĺʽh=ãt=
s
2龰ͼ
˶ΪٶΪȼֱ˶1t2t3tλ֮Ϊ135 ʵڶˮξĸ߶Ϊh=
=9=5m
𣺣1ÿˮʱ1.34s 2ʱ2ˮ5m
1. ⣺AڼٶʱͼУͼΧɵġٶȵı仯ͼ֪0-t0ʱٶȱ仯Ϊt0-2t0ʱڣٶȱ仯ΪҸı仯ı仯˵t0-2t0֮ijʱ̣ٶΪ㣬ʼ˶ABCȷ
Dͼ֪0-t0ʱڼٶȼСt0-2t0ʱڼٶȷٶȲǾȱ仯D ѡC ڼٶʱͼУٶȵı仯ʱϷΪ·Ϊͼġٶ˶ɣ
Ĺؼ֪a-tͼСٶȵı仯֪˶Уٶһֱ仯ѶУ 2. ⣺
ãa=
DȷABC
ٶʱ乫ʽã˶ʱΪt=
ѡD
ȱֱ˶ٶλƹʽʵ˶ļٶȣٶʱ乫ʽ˶ʱ䣮
Ĺؼȱֱ˶˶ѧʽãҲͨƽٶȵ˶ʱ䣮
3. ⣺ͨABBCCDʱֱΪTBٶȸݡx=aT2ãa=
=
=
6
vA=vB-aT==CȷABD
ѡC
ijʱڵƽٶȵмʱ̵˲ʱٶȣȵʱΪTBٶȣӶóAٶȣʱڵλ֮һٶȵĴСٸٶλƹʽ0Aľ룮
Ĺؼȱֱ˶ĹʽԼۣܽã
4. ⣺ͬѧֱ˶ͼΪбֱߣȻֹͼΪƽʱֱߣȻֱ˶λʱCȷABD ѡC
λʱͼбֱ߱ʾֱ˶ƽʱֱ߱ʾֹ
Ĺؼ֪λʱͼߵ壬֪ͼߵбʱʾٶȣ⣮
5. ⣺A.0-5s˶5-6s˶5sĩԶԶΪsm=2+510m=35mA
B0-5sλx1=2+510m=35m5-6sλx2=-110m=-5m·Ϊs=x1+|x2|=40mBȷ
C06sڣƽΪ===6.67m/s C
Dͼ֪56sظȼֱ˶ٶٶȷD ѡB
1v-tͼУʱƽеֱ߱ʾֱ˶бֱ߱ʾȱֱ˶бʱʾٶȣбԽʾٶԽͼΧɵʾλƣʱϷλΪ·ʾλΪ
2ƽʵ·̳ʱ䣻
3ȼֱ˶ٶٶȷͬ
ٶ--ʱͼӦüжϣҪȷбʵĺ壬֪ٶ--ʱͼͼΧɵĺ壬ܸͼȡϢҪע·̺λƵ 6. ⣺AͼбʵڼٶȣɵüٶȵĴС֮a1a2=
=21A
BλƵĴС֮Ϊx1x2=CDƽٶȵĴС֮Ϊ=
=12B
=11CȷD
ѡC ٶ-ʱͼУͼߵбʱʾٶȣͼΧλƣȱ˶ƽٶȿɹʽ
⣮
ٶ-ʱͼӦãҪȷбʵĺ壬֪ٶ-ʱͼͼΧɵĺ壮Ҫעʽ
ֻȱ˶
7
7. ⣺ɹʽx=2t+6t2֪ʼʱ̵λΪ
3sʱλΪ
m
3sλΪ x=x3-x0=60-0=60m ƽٶΪ
m/s
AȷBCD ѡA ȱֱ˶λʱ乫ʽʼʱλt=3sʱ̵λãȻƽٶȵĹʽ
⿴ȱֱ˶Ĺʽ⣬ʱҲԸȱֱ˶λʱ乫ʽijٶȺͼٶȣλƹʽλƣȻƽٶȣ
2
8. ⣺֪V0=10m/sa=-2m/sֹͣʱ ɲʱt=
=
s=5s
ɲʼ6sڵλƼΪ5sλ
X=t=t=5m=25m
ѡB
жɲʱ䣬ɲʱֱӴλƣɲʱɲʱλΪ˶λƣ ɲ⣬ؼжɲʱ䣬״㣺ɲʱͲ˶λƲٱ仯 9. ⣺Aٶʱλ֮x=25-1520=100mײɲʱľڵ100mAB
CٶȴٶСߣٶǰ߾СٶȺ߾֪ײֻܷٶ֮ǰһɲ20s֮ڵijʱ̷ײġCȷD ѡC
ٶȴٶСߣײٶʱС룻ǡòײٽ״̬ʱٶʱǡòײͼʱΧɵʾλƷжϣ
˶ѧе⣬ץסٽ״̬ǽĹؼ֪ٶʱײС룬ײֻܷٶ֮ǰ
10. ⣺ٶΪvmȼֱ˶ٶȴﵽȼֱ˶У
ȼٽγٶΪ0ĩٶΪvmȼٽεƽٶȣȼٽγٶΪvmĩٶΪ0ȼٽεƽٶȣ˶УƽٶȣٶȣѡC
8
=
=
CȷABD
=