全筆1AABD2（）態(tài)力動(dòng)：B：A；B錯(cuò)加3θ1kg為=10m/s斷20s220s2是（）t時(shí)化．0~動(dòng)角θ30°Ax5mv

v

=05ma=

0?2?

=

?100

=

v

=

v10m/st=

0??

=

?10?10

=1s1st=1sA?′

222

2

合A在0—1s，1s．有mgθmgcosθmamg﹣mgcosθ′得θ錯(cuò)選4所??????

???減小???小(??)?A?=?A??sin???????+?????(??)??

2

5AC????????在BC為g在cos為sinBCABFFmgFTF，=mgtanθcos?AC被力asinBACBCBCacos?6（”AA；BCD項(xiàng)D項(xiàng)B。BCD7（AA；BCDBDB8xFFBCAC

1

?x

?111???FA量故B；．，力做故。題940m/sg內(nèi)度；為θ對(duì)為g；為為37°靜，cos37°=0.8為。35

?tan

50為?=?sms1為

?s2[2]????tan3[3]?sin45??

?cos45

??

????

為，A、B4AA、B，A、B的1:2AB4mmA，???1B??+?1為??B2:1AB為?√?B√??A??

1√?11當(dāng)BA、B1:2力”“：

定

定：題37°力的由，數(shù)力F的（3

9.4N圖2?20?0.622?20?0.62－v＝2?

?2?

2

＝

220.5

＝?0.2m/s

2。y軸F＝FmgxFcos30°－＝maFcos30°－－Fsin30°maF示F0.5kg，H2s1加

）（1=4m/s；）；N11）?

?

?

?

m/s

2?????x軸?cos37

?°

??

′

?sin37

?

??

′

得?

m塊以板B知、B數(shù)μ之?dāng)?shù)，A滑板B塊A板110m/s

24mA????1111速度??m/s11

2；有??+(?????11速度?m/s

2右）AB都

?

A??1于??=???)?N111以，A繼??1=為?3?3

A1m/s×s?=s

2

1

m?

362

s1???sin37°????ms

22?2??m2

F′′?????1?3?????ms

?1

′

′

s??

s.11

d

222?222?121sdtts3mma

(2

2

1

1

2

(?+??1[1]cm+2mm2[2]2

?21

?1?

22212

?1(222

121

3[3]?(?+??

(?+?)??50Hz列3131??3131??v=__________m/sa

mm4.7

???(?????T?

???

?1.20)×10?2

m/s=m/s?????4?

(9.30?3.15?3.15)×102

2

2?????(?+?)?3113

???(?+??313??1每????

??

???

????

???

D____m/s________gm/s

E

0.5

E

T?

???

????

xaT?

???????

a

??

O1