2019届高三物理二轮复习专题八:《物理解题中的数学方法》训练含答案 - 百度文库 ر

Դ,ϺѿS2,ŵ,ֱŵϡʵѹӵļ¼ĵѹʱ仯u-tͼʾ,ͼΪɼͼҽݴ¼ġֵʱΧͼ

(1)ͼʾĵ·,۲ͼҿ֪:ŵ (ѡͬ෴),Сʱ (ѡӡ򡰼С)

(2)ͼȷõĵֵΪ F(2λЧ)

(3)ijͬѧΪ:װ,ѹӵ˸Ľڵ,ҲԲĵֵ˵ͬѧ˵Ƿȷ

? (2)C=??=??=??=???? m

m

m

m

??m

????

??

t????

C=1.010-2 F

(3)ȷΪS2ʱ,ŵĹ,CRϵĵѹС,ͨԷŵ߽ݴ¼ġֵUmʱΧS,ԿӦC==????

??????m

ֵ

? (1)෴ С (2)1.010-2

(3)

5.(ֵ)סͬһֱ߹ͬʻ,׳ǰ,ٶv1=8 m/s,ҳں,ٶ

v2=16 m/s,x0=8 mʱ,׳ʿʼɲ,ٶȴСa1=2 m/s2,Ϊײ,

ҳʼɲ,Ҫʹײ,ҳļٶΪ?

? ҳļٶȴСΪa2,׳λƺʱĹϵΪx=v1t-2a1t2

ҳλƺʱĹϵΪx=v2t-a2t2

21

1

λx+x0x,(a2-a1)t2+(v1-v2)t+x00

2

1

ֵ(a2-2)t2-16t+160

ʽa2-2>0,=162-416(a2-2)0 a26 m/s2

? 6 m/s2

6.(ֵ)ͼʾ,Сϵıֽ,ˮƽҵֽѸٳ,ƶС,۲첻,ǴϤĹʵ顣ֱֽΪm1m2,ӴĶĦΪ,ٶΪg:

(1)ֽ˶ʱ,ֽĦĴС (2)Ҫʹֽ˶,Сֵ

? (1)ֽĦСf1=m1g

ֽĦСf2=(m1+m2)g ֽĦСf=f1+f2=(2m1+m2)g

(2)ļٶΪa1,ֽļٶΪa2,ΪF,ţٵڶ

f1=m1a1,f1'=f1

F-f1-f2=m2a2

˶ʱ,a2>a1

F>2(m1+m2)g,ССֵ2(m1+m2)g

? (1)(2m1+m2)g (2)2(m1+m2)g

7.(ֵ)ͼʾ,ˮƽOϷװMÿȵʱɾֹͷһС,ijС뿪Mͬʱ,OҲһL=1.2 mƽ峵ʼa=6.0 m/s2ĺ㶨ٶȴӾֹʼ˶,Сǡƽ峵(С򲻵),֪ƽ峵ϱMֱ߶h=0.45 m,Կ,ٶgȡ10 m/s2

(1)ƽ峵Oˮƽ롣

(2)2Сƽ峵,ͷСʱtӦʲô?

? (1)Сƽ峵ϱ˴ʱt0,ڸʱ

Сh=2g??02 ƽ峵x=2a??02 x=0.27 m

11

(2)ͷŵһС2С䵽ƽ峵ϱʱt+t0,ƽ峵ڸöʱڵλΪx1,˶ѧ

x1=2a(t+t0)2

2Сƽ峵x1x+L æt0.4 s

1

? (1)0.27 m (2)t0.4 s

8.(ѧɷ)һСh0=45 mߴ,ŵغֵ,Ȼ,ÿһ,ٶȴСͱΪԭkk=,Сֱֹͣ˶õʱ䡣(gȡ10

21

m/s2,ײʱԲ)

? ˶ѧʽСÿһκڿ˶ʱͨʽ,Ȼ

Сh0䵽ʱٶv0=2???

0

˶ʱt0=

2???

0

һغС򷴵ٶv1=kv0=k2???

0

Сٴײ֮ǰֱ˶,˶,һС˶

2??1??

2???

ʱt1==2k

0

nغ,С˶ٶȵͨʽΪ

vn=kn2???

0

˶ʱtn=2??????

=2kn

2???

0

,С䵽ֹͣ˶ʱ