С. полый алюминиевый куб с ребром 10 см имеет массу 1 кг. какова толщина стенок куба? плотность алюминия 2700 кг/м^3 или 2, 7 г/см^3

S = 6*10^2= 600 (см^2)
p = 2 698 720 г / 1 000 000 см = 2,69872 г / см
б = m / (p * S) = 1 000 / (2.69872 * 600) = 0,6175 см

аквпикнр5е6пкраеркврин526462еач5кигач5а. 256н6е6а5крнпмннмн7м6пм6пм6пир7ир6мр6м6емнпмнпмнпву4а6ем4аеRead the text again and write next to the sentences True/False according to the text.

1. She looks after the big animals.

2. Her favorite animals are the tigers.

3. There are four elephants at the zoo.

4. Molly gets up at 6 o'clock.,

5. The lions eat salad.

6. The animals drink water.Read the text again and write next to the sentences True/False according to the text.

1. She looks after the big animals.

2. Her favorite animals are the tigers.

3. There are four elephants at the zoo.

4. Molly gets up at 6 o'clock.,

5. The lions eat salad.

6. The animals drink water.Read the text again and write next to the sentences True/False according to the text.

1. She looks after the big animals.

2. Her favorite animals are the tigers.

3. There are four elephants at the zoo.

4. Molly gets up at 6 o'clock.,

5. The lions eat salad.

6. The animals drink water.Read the text again and write next to the sentences True/False according to the text.

1. She looks after the big animals.

2. Her favorite animals are the tigers.

3. There are four elephants at the zoo.

4. Molly gets up at 6 o'clock.,

5. The lions eat salad.

6. The animals drink water.Read the text again and write next to the sentences True/False according to the text.

1. She looks after the big animals.

2. Her favorite animals are the tigers.

3. There are four elephants at the zoo.

4. Molly gets up at 6 o'clock.,

5. The lions eat salad.

6. The animals drink water.

Объяснение:

мнас5ас4аснач5км6кв5

v=

G∗M/R

m\frac{v_1^2}{R}=G\frac{Mm}{R^2};m

R

v

1

2

=G

R

2

Mm

;

v_1=\sqrt{G\frac{M}{R}};v

1

=

G

R

M

;

где m — масса объекта, M — масса планеты, G — гравитационная постоянная (6,67259·10−11 м³·кг−1·с−2), v_1\,\!— первая космическая скорость, R — радиус планеты. Подставляя численные значения (для Земли M = 5,97·1024 кг, R = 6 371 км) , найдем

v_1\approx\,\!v

1

≈

7,9 км/с

Первую космическую скорость можно определить через ускорение свободного падения — так как g = GM/R², то

v1=\sqrt{gR};.v1=

gR

;.

Космические скорости могут быть вычислены и для поверхности других космических тел. Например на Луне v1 = 1,680 км/с