My model is supposed to have

What are the three types of friction and when does each apply

Annette [7]

Sliding: when an object slides across a surface
rolling: when an object rolls across a surface
static is when something ain't moving

4 0

4 years ago

The radius of the aorta is «10 mm and the blood flowing through it has a speed of about 300 mm/s. A capillary has a radius of ab

stealth61 [152]

Answer:

(I). The effective cross sectional area of the capillaries is 0.188 m².

(II). The approximate number of capillaries is $3.74\times10^{9}$

Explanation:

Given that,

Radius of aorta = 10 mm

Speed = 300 mm/s

Radius of capillary $r=4\times10^{-3}\ mm$

Speed of blood $v=5\times10^{-4}\ m/s$

(I). We need to calculate the effective cross sectional area of the capillaries

Using continuity equation

$A_{1}v_{1}=A_{2}v_{2}$

Where. v₁ = speed of blood in capillarity

A₂ = area of cross section of aorta

v₂ =speed of blood in aorta

Put the value into the formula

$A_{1}=A_{2}\times\dfrac{v_{2}}{v_{1}}$

$A_{1}=\pi\times(10\times10^{-3})^2\times\dfrac{300\times10^{-3}}{5\times10^{-4}}$

$A_{1}=0.188\ m^2$

(II). We need to calculate the approximate number of capillaries

Using formula of area of cross section

$A_{1}=N\pi r_{c}^2$

$N=\dfrac{A_{1}}{\pi\times r_{c}^2}$

Put the value into the formula

$N=\dfrac{0.188}{\pi\times(4\times10^{-6})^2}$

$N=3.74\times10^{9}$

Hence, (I). The effective cross sectional area of the capillaries is 0.188 m².

(II). The approximate number of capillaries is $3.74\times10^{9}$

3 0

3 years ago

HELP!! ALL MY POINTS WILL BE GIVEN

Marta_Voda [28]

Answer:

-6 m/s^2

Explanation:

30 - 90 = -60

-60 / 10 = -6

If acceleration was constant, it will be -6 m/s^2

5 0

2 years ago

Read 2 more answers

A rocket in orbit just above the atmosphere is moving in uniform circular motion. The radius of the circle in which it moves is

Zinaida [17]

Centripetal acceleration is given by the formula

$a_{cen}= \frac{v^2}{r}$

Since we know the value of the acceleration is 9.8 m/s² and we know r, we can solve for the speed, which is the magnitude of v. Note the value of a is just the acceleration due to gravity, which is what makes the rocket orbit and not fly off into space.

$9.8 \frac{m}{s^2}=\frac{v^2}{6.381 \times 10^6m} \\ \\ 9.8 \frac{m}{s^2} \times 6.381 \times 10^6m=v^2 \\ \\ v= \sqrt{9.8 \frac{m}{s^2} \times 6.381 \times 10^6m} =24755 \frac{m}{s}$

8 0

3 years ago

A nuclear accident (intentional or unintentional) can cause significant harm to those living nearby or at a distance. Harmful le

Vladimir [108]

Answer:

(C) Contact

Explanation:

Radiation Poisoning is a horrific disease that is transmitted in many ways. After a nuclear accident radiation is released into the atmosphere becoming airborne and affecting everyone that breathes it in. It is also transmitted in droplets from acid rainfall. Once the gamma radiation penetrates the body of a person it can contaminate other people by having skin to skin contact with the person that is contaminated. Therefore it can be prevented by having precaution of direct contact with anyone contaminated.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

4 0

3 years ago