bài 1 - đại cương dao động điều hòa

T [s]

f [Hz]

N

T f

Trong đó:

x –

A –

–

( t+ ) – –

htttp://tuhoc.edu.vn/blog

A –3 cm; – /4 B –3 cm; /4

C 3 cm; 3 /4 D 3 cm; /4

3

A 6 cm B –6 cm C 12 cm D –12 cm

4

A 3 cm B 5 cm C 8 cm D 4 cm

5

A 2cm; 0,5s B 2cm; 2s C 4cm; 0,5s D 4cm; 2s

6

A T = 3s B T = 2s C T = 0,5s D T = 1s

v x A sin( t )

max = A vmin = 0

cm/s; m/s

max = A 2222 amin = 0

2 2 2

2

o

o

htttp://tuhoc.edu.vn/blog

8

9

A

A 25,12cm/s B 25,12m/s

C 12,56cm/s D 12,65cm/s

B

A 62,8cm/s B 62,8cm/s

C – 62,8 cm/s D 31,4 m/s

C

A -947,5cm/s2 B 947,5cm/s2

C -74,5cm/s2 D.74,5cm/s2

D

2

E

2 = 10

A 25cm/s; 5m/s2 B 5 cm/s; 250cm/s2

C 5 cm/s; 2 m/s2 D 10 cm/s; 2m/s2

x 5cos(2 t /3)cm

x 5cos(2 t /2)cm

x P x

M0 O

0,

t+ )

x OP OMcos( t ) Acos( t )

htttp://tuhoc.edu.vn/blog

-A A x

O

x 1 x 2

x Acos( t ) A cos

1

cos

A

1 2

B3:

.T t

2

x2 = A/2 ?

A T/6 B T/12 C T/4 D T/2

1 2 6

B1:

B2:

-A A x

O

30 o

1 2

A 0

B

A 2

-A A x

O

x 1 x 2

x Acos( t ) A cos

B1:

B3:

.T t

2

B2:

VD:

A 1/3s B 1/8s C 1/6s D 1/4s

-8 8 x O 90

o

B

1 1

trí x1:

1 1

v 0

B1:

B2:

B3:

2

x 2 x 1

âm

1 t

4

htttp://tuhoc.edu.vn/blog

-A A x

O

x 1 x 2

B1:

B2:

B3:

1 = n.4A 2

-2 2 x90 O

o

trí x1: và x2:

x 2 x 1

1 1

v dÊu > | <

2 2

v dÊu > | <

S = S1 + S2

t n.T t ( t T)

4A 2A chưa A

VD:

2 = 61T/24 là:

B1:

1 = 7T/24: 1

1

2 = 61T/24: 2

2

B2:

S S1 S2

B3:

– S1 có: S2 = A = 2cm

1 + S2 = 18cm

C

-A A x

O

x 1 x 2

B1:

B2:

1 1 = n.T 2

-5 5 x

O

t = t1 + t2

4A 2A chưa A

là:

A 41/6(s) B 27/4(s) C 20/3(s) D 13/2(s)

B1:

0

S n.4A s

S = 67,5cm =3.4.5 + 7,5

t = t1 + t2

B2:

– t1 = 3.T = 6s – t2

2,5

150 o

A

41

6

htttp://tuhoc.edu.vn/blog

-A A x

O

x 1 x 2

B1:

B2:

-3 3 x

O

B1:

1 1,5

t n.T t

x 0

2 1

2 5

t t

B2:

B

-A A x

O

x 1 x 2 n = 2k

n = 2k

-4 4 x

O

x 0

x 0

x 4cos(4 t /6)cm

12061 s

24

B1:

x 0

B2:

= 2cm là 1005T

):

1005

2 3

o

30

T t

T 12061

htttp://tuhoc.edu.vn/blog

-A A x

O

x 1 x 2

B2:

B3:

t

-10 -6 6 10 x

O

o

A x = 5cm B x = 6cm C x = –5cm D x = –6cm

B1:

B2:

B

0,5.2 rad

-A -A/2 A x

O

không (0).

VD:

2T

9A 4T

A 2T

5A 2T 3A S 2

trong đó |x2 – x1

1 2

2 1 tb

2 1

x v

2 1

S v

t t

3A

v

T

3

A

htttp://tuhoc.edu.vn/blog

-A -A/2 A x

O

VD:

max

A 1,5A B 2A C A 3 D 3A

2T T T t

1 = 2A

1 + S2 = 3A

D

t < T/2

max

2 min

2

t > T/2, t' < T/2 Tách: t n.T/2 t max

S 2A 2A.sin

2 n

min

S 2A 2A.(1 cos )

2 n

3

3 2

S 2Acos( ) A

2

G

A 2T/3 B T/4 C T/6 D 5T/12

H

A 5T/4 B T/4 C.2T/3 D.3T/4

I

Qu

A S = 12 cm B S = 24 cm

C S = 18 cm D S = 9 cm

Qu

A S = 12 cm B S = 24 cm

C S = 18 cm D S = 9 cm

L

A 2 2

A 3 2

htttp://tuhoc.edu.vn/blog

π/6) (x t

6)

A t = 61/6 (s) B t = 9/5 (s)

C t = 25/6 (s) D t = 37/6 (s)

S

A t = 4,5 (s) B t = 2,5 (s) C t = 2 (s) D t = 0,5 (s)

T

A t = 5/6(s) B t = 11/6(s) C t = 7/6(s) D 11/12 (s)

A -2cm B 2cm C D -

=

A 2cm B - cm C - cm D cm

X

Y

A 9A/2T B 4A/T C 6A/T D 3A/T

Trong 1 (s)

2 3

2

htttp://tuhoc.edu.vn/blog

C Smin = 0,5 m D Smin = 4 m

A Smax = 7,07 cm B Smax = 17,07 cm

C Smax = 20 cm D Smax = 13,66 cm

A Smin = 13,66 cm B Smin = 12,07 cm

C Smin = 12,93 cm D Smin = 7,92 cm

A Smax = 12 cm B Smax = 10,92 cm

C Smax = 9,07 cm D Smax = 10,26 cm

A 1/15 s B 2/15 s C.1/30 s D 1/12 s

A 1/4 s B 1/2 s C 1/6 s D 1/12 s

1 D

g h i j