Are chemical reactions necessary in life

The buildup of plaque on the walls of an artery may decrease its diameter from 1.1 cm to 0.90 cm. The speed of blood flow was 17

natka813 [3]

Answer

Initial radius of the artery is (1.1 cm) / 2 = 0.55 cm

final radius of the artery is (0.90 cm) / 2 = 0.45 cm

initial velocity of the blood is 17 cm/s

Using equation of continuity is

A₁v₁=A₂v₂

π r₁² x v₁ = π r₂² x v₂

r₁² x v₁ = r₂² x v₂

0.55² x 17 =0.45² x v₂

v₂=25.39 cm/s

Bernoulli's equation is

$P_1 - P_2 = \dfrac{1}{2}\rho (v_2^2-v_1^2)$

rho is the density of blood = 1060 kg/m^3

$P_1 - P_2 = \dfrac{1}{2}\times 1060 \times (0.254^2-0.17^2)$

$P_1 - P_2 =18.87\ Pa$

6 0

3 years ago

How are doctors both accurate and precise when preforming surgery or other things?

mr Goodwill [35]

Answer:

learning about the different functions of the body and therefore they have enough practice in order to have a clean and safe operation

Explanation:

4 0

3 years ago

A fluid moves through a tube of length 1 meter and radius r=0.002±0.0002 meters under a pressure p=4⋅105±1750 pascals, at a rate

yaroslaw [1]

Answer:

The maximum error is $\Delta \eta = 2032.9$

Explanation:

From the question we are told that

The length is $l = 1\ m$

The radius is $r = 0.002 \pm 0.0002 \ m$

The pressure is $P = 4 *10^{5} \ \pm 1750$

The rate is $v = 0.5*10^{-9} \ m^3 /t$

The viscosity is $\eta = \frac{\pi}{8} * \frac{P * r^4}{v}$

The error in the viscosity is mathematically represented as

$\Delta \eta = | \frac{\delta \eta}{\delta P}| * \Delta P + |\frac{\delta \eta}{\delta r} |* \Delta r + |\frac{\delta \eta}{\delta v} |* \Delta v$

Where $\frac{\delta \eta }{\delta P} = \frac{\pi}{8} * \frac{r^4}{v}$

and $\frac{\delta \eta }{\delta r} = \frac{\pi}{8} * \frac{4* Pr^3}{v}$

and $\frac{\delta \eta }{\delta v} = - \frac{\pi}{8} * \frac{Pr^4}{v^2}$

So

$\Delta \eta = \frac{\pi}{8} [ |\frac{r^4}{v} | * \Delta P + | \frac{4 * P * r^3}{v} |* \Delta r + |-\frac{P* r^4}{v^2} |* \Delta v]$

substituting values

$\Delta \eta = \frac{\pi}{8} [ |\frac{(0.002)^4}{0.5*10^{-9}} | * 1750 + | \frac{4 * 4 *10^{5} * (0.002)^3}{0.5*10^{-9}} |* 0.0002 + |-\frac{ 4*10^{5}* (0.002)^4}{(0.5*10^{-9})^2} |* 0 ]$

$\Delta \eta = \frac{\pi}{8} [56 + 5120 ]$

$\Delta \eta = 647 \pi$

$\Delta \eta = 2032.9$

4 0

4 years ago

When a child does not know how to react emotionally to a situation they will observe the emotional expressions of others. This i

Otrada [13]

Answer:

4)

social referencing

6 0

4 years ago

What are the factors that affect ocean density?<br><br> Please help!!

Paul [167]

The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. long story short, seawater is the problem because its denser than pure water.

6 0

3 years ago

Read 2 more answers