a ) Lực đẩy của Acsimet là :

F_A = 2,4 - 1,8 = 0,6 ( N )

Thể tích của vật là :

V_v = 0,6 : 10000 = 0,00006 ( m³ )

b ) Chất làm vật có trọng lượng gấp :

d = P : V = 2,4 : 0,00006 = 40000 ( kg/m³ )

Áp dụng d : d_n ta kết luận gấp 4 lần

Thể tích của vật đó là :

V = m : D = 598,5 : 10,5 = 57 ( cm³ )

Đổi : 57cm³ = 0,000057 m³

Lực đẩy Acsimet tác dụng lên vật là :

F_A = d.V = 10000.0,000057 = 0,57 ( N )

Đáp số :...

\(n_{HCl}=0,1\cdot1,5=0,15\left(mol\right)\)

Pt : \(NaOH+HCl\rightarrow NaCl+H_2O\)

0,15 mol \(\leftarrow\)0,15mol

\(V_{NaOH}=\dfrac{0,15}{1}=0,15\left(l\right)=150\left(ml\right)\)

\(x\left(x^2-y\right)-x^2\left(x+y\right)+y\left(x^2-x\right)\)

\(=x^3-xy-x^3-x^2y+x^2y-xy\)

\(=-2xy\)

1. We (not, go)_______won't go_______ to school tomorrow.

2. Sarah (paint) _______will paint__________ the picture later.

3. He (work) ______works____________ hard every day.

4. She (talk) ________is talking__________ to Peter now.

5. Mr. Green (not, be) ______wasn't____________ in his office yesterday morning.

6. We (not, sell) _________didn't sell__________ our house last month.

7. They (not, be) _______weren't_____________ at home last night.

8. They (buy) __________bought_________ a new LCD TV set last week.

9. We (finish) _____finished____________ the work yesterday.

10. My mother (work) ________is working__________ in her office at this moment.

1.There is a magazine on the table.

The magazine is on the table.

2.Lan is Hung's younger sister

Hung is Lan's older brother

3.Mai is Mrs.Hong's daughter

Mrs.Hong is Mai's mother

4.The weather today is very nice

What nice weather !

5.These books are very interesting

What interesting books!

Bài tham khảo của người khác :)

1) Hurry up or the train.............. before you catch it.

A. Will leave B. leaves C. will have left D. has left

2) A football team............... chiefly of 12 players.

A. composed B. composes C. comprised D. comprises

3) .............. to rain before you woke up this morning?

A. Did it begin B. has it begun C. Had it begun D. would it begin

4) My daughter saw an elephant this morning but she........... one before

A. had never seen B. has never seen C. never seen D. never had seen