D

D

A

Biên độ dao động càng lớn thì âm phát ra càng to.

a

a: -1/6=-3/18

-5/9=-10/18

-7/9=-14/18

b: -1/3=-10/30

-1/5=-6/30

-1/10=-3/30

c: 19/22=57/66

5/6=55/66

-29/33=-58/66

tk 

 1. Hoa sister is listening to music in her room at the moment.

2. Do you watch TV or play sport after school ?

3. What does your sister often play in the morning ?

4. They don't listen to music after dinner.

5. Which is the most suitable house for Mr.Lan and his family?

D

A = F . s = 6000.1000 = 6000000 ( J )

 tick minh nha :))