1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Rudiy27
3 years ago
10

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

out 4ˆ10´3 mm but there are literally billions of them. The average speed of blood through the capillaries is about 5ˆ10´4 m/s. (i) Calculate the effective cross sectional area of the capillaries and (ii) the approximate number of capillaries.
Physics
1 answer:
stealth61 [152]3 years ago
3 0

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}

You might be interested in
Organism would make the best index fossil. Answers a , b , c , d please help
aivan3 [116]

Answer: You didn't put what a, b, c, or d is so how is anyone supposed to know what the answer is?

5 0
3 years ago
Read 2 more answers
386.5<br>- 129.18 what is it​
algol [13]

Answer:

257.32

Explanation:

I jus worked it out on paper. Brainliest please?

5 0
3 years ago
Read 2 more answers
If a boat and its riders have a mass of 900 kg and the boat drifts in at 1.4 m/s how much work does sam do to stop it?
Rama09 [41]
The initial kinetic energy of the boat and its rider is
K_i =  \frac{1}{2} mv_i^2 =  \frac{1}{2}(900 kg)(1.4 m/s)^2=882 J

After Sam stops it, the final kinetic energy of the boat+rider is
K_f = 0 J
because its final velocity is zero.

For the law of conservation of energy, the work done by Sam is the variation of kinetic energy of the system:
W=K_f-K_i =0-882 J=-882 J
where the negative sign is due to the fact that the force Sam is applying goes against the direction of motion of the boat.
6 0
3 years ago
A car changes its speed by 2 meters per second each second. What is its acceleration?
KatRina [158]

Answer:

2 m/s²

Explanation:

If changes speed by 2 meters per second each second means:

2 m/s²

Because it changes constantly it veloctity.

Remember the aceleration changes the velocity.

4 0
3 years ago
Read 2 more answers
If grade 7 students learn six periods and if one period is 40 minutes then how many seconds they learn per day
Ludmilka [50]

Answer:

C. 14400

Explanation:

40min × 6 periods = 240mins total.

1 minute = 60 seconds.

240 minutes × 60 = 14400 seconds.

6 0
3 years ago
Read 2 more answers
Other questions:
  • Mary just received a traffic ticket but decided it is not worth being upset about. Mary just made a__________.
    15·1 answer
  • A ladder is leaning against a vertical wall, and both ends of the ladder are at the point of slipping. The coefficient of fricti
    8·1 answer
  • A dart leaves a toy dart gun with initial velocity of 7.76 m/s, regardless of the angle it is fired. What is the maximum horizon
    13·1 answer
  • This power is generated from a renewable resource; however, it still has some of the negative effects associated with using powe
    6·2 answers
  • Exercise 15.1 (a) Find the magnitude of the electric force between two protons separated by 1 femtometer (10^-15), approximately
    15·1 answer
  • To practice Problem-Solving Strategy 25.1 Power and Energy in Circuits. A device for heating a cup of water in a car connects to
    5·1 answer
  • Which has is a product of photosynthesis? A. Carbon Dioxide B. Oxygen C. Hydrogen.
    10·2 answers
  • ) What is the electric potential due to the nucleus of hydrogen at a distance of 7.50× 10-11 m? Assume the potential is equal to
    13·2 answers
  • if a car is moving with a speed of 50km/s then calculate the distance covered by the car in 20 seconds
    8·2 answers
  • Why do natural polymers not pose as much of an issue in landfills as synthetic polymers?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!