Phân loại và phương pháp giải các bài toán chuyển động cho học sinh khá, giỏi toán lớp 5

MỤC LỤC

MỞ ĐẦU 1
1.  1
 3
 3
 3
 3
 3
 4
CHƢƠNG 1. CƠ SỞ LÍ LUẬN VÀ THỰC TIỄN 5
1.1. Vai trò  toán 5
1.2.  6
 6
 
TT 8
 11
CHƢƠNG 2. PHÂN LOẠI VÀ PHƢƠNG PHÁP GIẢI CÁC BÀI TOÁN
CHUYỂN ĐỘNG CHO HỌC SINH KHÁ, GIỎI TOÁN LỚP 5 12
 12
 12
 12
2.2. 



 các  ,
5 13
2.2.1. Các btham gia 13
2.2.2. 2 


3 





 23
2.2.3.  28
2.2.4.  34
 39
 43
CHƢƠNG 3. THỰC NGHIỆM SƢ PHẠM 44
3.1.   44
 44
 44
 44
 44
 44
 44
 44
 45
 47
 47
 47
 48
KẾT LUẬN 49
TÀI LIỆU THAM KHẢO 49

1
MỞ ĐẦU


1. Lí do chọn đề tài
 - xã
 
   
khô và

truy
g 
 
vô cù




 







 



 
   sinh phát huy
 


2



, 
          

chu .


     


 
 


c 
t 
  




n




 “Phân loại và phƣơng pháp giải các bài
toán chuyển động cho học sinh khá, giỏi toán lớp 5” 


3

2. Mục đích nghiên cứu
- Phicác bài toán
oán 5
- .
- .
3. Nhiệm vụ nghiên cứu

-  

.
-  
   các 
.
- .
4. Đối tƣợng và phạm vi nghiên cứu
-             
sinh khá, 
-  
  khá, 5

5. Khách thể nghiên cứu
Giáo viên khá,  T 8  4,

6. Phƣơng pháp nghiên cứu

 - quan sát





4
7. Cấu trúc của đề tài

ng 1. .

oán 5.
 .


5
CHƢƠNG 1. CƠ SỞ LÍ LUẬN VÀ THỰC TIỄN

1.1. Vai trò của giải toán trong quá trình dạy học toán



- 



- 


- 

 


Lưu ý













6


1.2. Mục đích, yêu cầu của việc dạy học giải toán chuyển động
 
- 

- ,  so sánh, suy


- ng và

- 

1.3. Phƣơng pháp chung để giải các bài toán
 

 








  . Thông
 


   




7

Tìm cách 
quy

là 




  





 

*  - tìm




Theo Cht trong
 trình

t






8




trí nà

- 

- 
- 
- 



1.4. Thực trạng việc dạy và học toán chuyển động cho học sinh khá, giỏi
toán lớp 5 ở một số trƣờng tiểu học.

Tu  cách
 .
 giáo viên:

T


giáo
viên




1 
10

10 
20
Trên
20


Cao

Trung


Khá
Trung
bình


8  4

7

3

2

2

3

4

0

4


3

0


9
t 
ta 
-  
trong sách giáo khoa, 

, .
- 
  Tuy


 
            




B




sinh


Khá
Trung bình


T

8  4
5A
25
10
15
0
0
5B
26
9
17
0
0

- Chúng  
 4 


 vào

10
làm  trong sách giáo khoa


 










11
TIỂU KẾT CHƢƠNG 1



 
               các

va 
 và 

  
  
  em
n cách phâ

 
sinh khá 

   
i
  khá,
 










12
CHƢƠNG 2. PHÂN LOẠI VÀ PHƢƠNG PHÁP GIẢI CÁC BÀI TOÁN
CHUYỂN ĐỘNG CHO HỌC SINH KHÁ, GIỎI TOÁN LỚP 5

2.1. Nội dung các bài toán chuyển động ở lớp 5 và một số kiến thức liên quan
2.1.1. Nội dung các bài toán chuyển động ở lớp 5
         


- 
- 

+ 


 
- 






2.1.2. Một số kiến thức liên quan

- 
- 
- 


- : s = v × t
- : v = s : t
- : t = s : v
v = s : t
t = s : v
s = v × t

13










 là m/giây.

-  


-  


-         

.
2.2. Phân loa
̣
i va
̀
phƣơng pháp giải các bài toán chuyển động cho học sinh
khá, giỏi toán lớp 5
2.2.1 Bài toán c một chuyê
̉
n đô
̣
ng tham gia
a. Kiến thư
́
c cần nhơ
́

- 

= :  (t = s : v)
= g

 





 



(

)
+ G





= 

n  

 




(

)
+ G

= 





+ 

+ 



(

)
- 

 = : 

 (v = s : t)
-  = 

 


 (s = v × t)



14
b. Các dng bi
4 :
- Dạng 1: 


















.
- Dạng 2:  













.
- Dạng 3: 





 1 


, 



.
- Dạng 4: 
c. V d
Bài toán1: 










45km/h 
12 

. N









35km/




40 . n B
* 

 - :

- 

1 



, bài toán thuc dng 1.
+  1 ô t

  






 ia



 , 

















40 
+ 

: s = 





= 

 


+ 























.
+ 











: 

1 , 









2 



















. 


















a ô tô.
* 



:
- 








2 


: 45 : 35 =
9
7



15
- 

1  2 






. 

















9
7







7 







9 


:






:






:











:
40 : (9  7) × 9 = 180 ()
(180 = 3 

)
:
3 × 35 = 105 (km)



: 105 km
* 









gii:
- Ki, 



 



 .
- i :
.




 





40 : (9 - 7) × 7 = 140 ()
140 =
7
3




45 ×
7
3
= 105 (km)


: 105 (km)
Bài toán 2: 







 3 









10 








1 

. 

?
40 phút

16
* 

 :
+ 1 



, bài toán thuc dng 2.
+  AB. 




= v × t
+  



 3 





 
1 





















 








.
+ 














2 

















+ 10



a 2 v






2 
















 











* 




:






: 3 + 1 = 4 (gi)














2 













nhau.  





3 : 4 =
3
4
















:
4
3







4 







3 


:




:






:







:
10 : (4 - 3) × 4 = 40 (km/h)
:
40 × 3 = 120 (km)


: 120 km

10km

17
* 












:
- 

m tra,  



.
- C 




:










:
10 : (4 - 3) × 3 = 30 (km/h)
:

30 × 4 = 120 (km/h)


: 120 km.
Bài toán 3:
Bài 3a: 











 3 

41 

















 .
Khi xu







 6km/






5km/



 4km/h.  ? (
9km)
* 


- :
-  



, bài toán thuc dng 3.
-  3 

41 
 6km/



 4km/








5km/





9km.
- 


:
+ 







 , 










255 3 

45 
+ 



















221. 4 .




, 





.
* 



:





:




A
B
6 km/h
4 km/h
5 km/h

18




















.






1

:
60 : 4 + 60 : 6 = 25 ()




1



:
60 : 50 × 2 = 24 ()








:
25 × 9 = 225 () = 3 

45 














:
3 

45 phút  3 

41 = 4 ()


1






1 



:
25  24 = 1 ()
 4 
ngang










:
4 : 1 = 4 (km)


: 4 km
* 












:
- 

m tra,  

.
Bài 3b:  .  2




 : 1 



1 

 . 5 

15 









 1 





 10 

15 .
 . 



 3 km/






 5 km/


.
* Ph

 :
- ng tham gia và thuc dng 3.
- .

19
-  5 

15 
 

1 

, 



 10 

15 . 



 3km/

,
5km/


.
- 











: s = v × t. 








. 



















.
- 



= 

 



 






= 10h15p  1h  5h15p = 4 



+ 
3
5













 2 









.



, 
5
3
. 










lên d

.
* 



:






:






















10 

15  1 


 5 

15 = 4 












  1 

 1
 . 

2 



 2 











n ch.
A
C
B
(nhà)


20
 3 : 5 =
3
5





 , 








 2 









 . 

, 







5
3



:



 gian lên dc :

Thi gian xung dc :



:
4 : (5 + 3) × 5 = 2,5 (

)
:
3 × 2,5 = 7,5 (km)




: 7,5 km
* 









:
- 


m tra,  



 và các phép tính.
- 







.
:






:
4 : (5 +3) × 3 = 1,5 (

)




:

5 × 1,5 = 7,5 (

)


: 7,5 


Bài toán 4: 

































 . 






 60 km/

, 

40km/g

.  

2 







.



21
* 

 T:
- 1 



, bài toán thuc dng 4.
-  , 



60km/

, trong
1 





40 km/gi. 50 km/



- 











2 



2  
.
- 



















-  ?
* 



:
-  

 60 km/

. Nên lú

 




1 




1 : 40 =
1
40
(

) = 1,5 
- 





2km, 1

1, 





1 + 1,5 = 2,5 ()











1




2,5 : 2 = 1,25 ()
:
11,25 
i trong 1 

(hay 60 )






1 



:
60 : 1,25 = 48 (km/

)


: 48 km/



* 











:
- 

, 

 



và các .
- 

:
 




 



22
:

60
s
(

)




, :

40
s
(gi)


, 










:

60
s
+
40
s
=
2
120
s
+
3
120
s
=
5
120
s
(

)
2s 






2
:
2 × s :
5
120
s
= 2 × s ×
120
5 s
=
2 120
5

= 48 (km/

)


: 48 km/


c. Mô
̣
t số ba
̀
i luyê
̣
n tâ

̣
p
Bài 1: 











nh B. N



30km/








 1 












 . 



 20
km/





1 










. H








?
2: 













 30km/

.









 25 km/





2 










. .
3:  
3 

, 



















14km/

. 







 1 







. .
4:  1 



 1 

. 




25 km/







50 km/

. 









7,5 

. .

23
5: 











 12 km/

. 













 10 km/

. 












.
2.2.2 Các bài toán c 2 hoă
̣
c 3 chuyển động cng chiu tham gia
a. Kiến thức cần nhơ
́
.
- 




 



: v
1

- 









: v
2

- 2 







 






 
 









: t = s : ( v
1
+ v
2
)
- 



 2 



1 

















2 : t = v
2
× t
0
: ( v
1
+ v
2
)
(

i v
2
×t

0
 2 










0
)
b. Các dng bi
- Dạng 1: 







 1 



- Dạng 2: 








1 





 



1


t
0
.
- Dạng 3: 3 





.
c. V d
Bài toán 1:  12 














 60
km/







 3 

30 . C trên







40 km, m





40 km/


. H2 









?
* 

 T:
- 2 chuy

, bài toán thuc dng 1.
-  m 2 















:
+ 





12 

, 





3 

30 

 



60 km/ 


+ 





40 , 



45 km/

.