Suppose the flow rate of blood in a coronary artery has been reduced to half its normal value by plaque deposits. By what factor has the radius of the artery been reduced, assuming no turbulence occurs?
Strategy
Assuming laminar flow, Poiseuilleâs law states that
Q = (p2 - p1)pir^4/8nl.We need to compare the artery radius before and after the flow rate reduction.

Answers

Answer 1

Answer:

1.18

Explanation:

The flow rate of blood is proportional to the fourth power of its radius as given the Poiseuille's law.

The law is :

[tex]$Q \propto r^4$[/tex]

It is given here that the flood flow rate is been reduced to half its normal value. Therefore, [tex]$Q_1 = \frac{1}{2}Q_2$[/tex]

So, for the radius [tex]$r_1$[/tex] and [tex]$r_2$[/tex], the ratios of their flow rates are :

[tex]$\frac{Q_1}{Q_2}=\frac{r_1^4}{r_2^4}$[/tex]

It is given that the flow rate is reduced to half. So we have,

[tex]$\frac{Q_1}{2Q_1}=\frac{r_1^4}{r_2^4}$[/tex]

or [tex]$r_2=2^{1/4}{r_1}$[/tex]

[tex]$r_2=1.18 \ r_1}$[/tex]

So the radius changes by a factor of 1.18


Related Questions

F = 5 Newtons
W = 75 Joules
d = ?

ANSWER

Answers

Substitution: d = 75 J/5 N
Answer with unit of measure: d = 15 m

What is gravitonal force

Answers

Answer:

its something that hold the air for forceing liy by the exgen

Explanation:

How do unbalanced forces acting on an object affect its motion when the object is at rest? What if it is moving?

Answers

Answer:

It pushes it because an unbalanced force is pushing more newtons than something that isn't even moving. Even if it is moving, it depends which side is pushing/pulling the most force.

Explanation:

Answer:

It pushes it because an unbalanced force is pushing more newtons than something that isn't even moving. Even if it is moving, it depends which side is pushing/pulling the most force.

Which of the following locations will be relatively warmer during summers, and why? A. An inland location, because water heats up faster than land.
B. A coastal location, because water heats up faster than land.
C. A coastal location, because water has higher specific heat than land.
D. An inland location, because land has lower specific heat than water.​

Answers

D - An inland location, because land has lower specific heat than water

Explanation:

The specific heat is a measure of how much heat must be supplied to warm up a substance by a certain number of degrees.
Water has a much higher specific heat than land, so it takes much more heat energy to heat up a given mass of water compared to the land.
To say it another way, the specific heat of land is much less than that of water, so it doesn't take as much heat energy to warm up the land.
Thus, an inland location will be relatively warmer during summers.

In the video your blood is compared to a __________________ that delivers oxygen to your body and picks up CO2 to be released out when you breath.

Answers

Answer:

delivery truck

Explanation:

because i got it right

I have a pen
I have a apple
what do I have now?

Answers

Answer:

You have an apple pen. :)

Answer:

I have a pen

I have a apple

apple pen

Explanation:

What voltage is required to move 6A through 5Ω?

Answers

30 volts

E= IxR

See ohms law calculator image below

An experiment consists of throwing balls straight up with varying initial velocities. Which quantity will have the same value in all trials?a) initial momentum.
b) maximum height.
c) time of travel.
d) acceleration.

Answers

Answer:

the correct answer is D,  acceleration of gravity

Explanation:

In a projectile launch problem it is described by the expressions

        v = v₀ - g t

         v² = v₀² - 2 g y

        y = v₀ t - ½ g t²

By examining these equations we can see that acceleration is the magnitude that appears constant in all expressions.

 This acceleration is the acceleration of gravity with a value of g = 9.8 m/s² and directed towards the center of the Earth

therefore the correct answer is D

What is the result of increasing the speed at which a magnet moves in and
out of a wire coil?
A. The current in the wire increases.
B. The magnetic field around the magnet decreases.
C. The current in the wire decreases.
D. The magnetic field around the magnet increases.

Answers

Answer:

A. The current in the wire increases.

Explanation:

Increasing the speed at which a magnet moves in and out of a wire coil increases the current in the wire.

This phenomenon shows the inter-relationship between electricity and magnetic fields.

Magnetic fields are induced by passage of electric current. Also, electric current can be produce by magnetic fields. When the speed at which a magnet moves in and out of a wire coil increases, the current also increases.

A stereo speaker is placed between two observers who are 35 m apart, along the line connecting them. If one observer records an intensity level of 64 dB, and the other records an intensity level of 85 dB, how far is the speaker from each observer

Answers

Answer:

   x = 2,864 m ,       Ra = 32.1 m                       

Explanation:

Let's solve this problem in parts, let's start by finding the intensity of the sound in each observer

observer A β = 64 db

             β = 10 log Iₐ / I₀

where I₀ = 1 10⁻¹² W / m²

              Iₐ = I₀ 10 (β/ 10)

let's calculate

              Iₐ = 1 10⁻¹² (64/10)

              Iₐ = 2.51 10⁻⁶ W / m²

Observer B β = 85 db

             I_b = 1 10-12 10 (85/10)

             I_b = 3.16 10⁻⁴ W / m²

now we use that the emitted power that is constant is the intensity over the area of ​​the sphere where the sound is distributed

              P = I A

therefore for the two observers

              P = Ia Aa = Ib Ab

the area of ​​a sphere is

               A = 4π R²

we substitute

               Ia 4pi Ra2 = Ib 4pi Rb2

               Ia Ra2 = Ib Rb2

Let us call the distance from the observer be to the haughty R = ax, so the distance from the observer A to the haughty is R = 35 ax; we substitute

             Ia (35 -x) 2 = Ib x2

we develop and solve

           35-x = Ra (Ib / Ia) x

           35 = [Ra (Ib / Ia) +1] x

           x (11.22 +1) = 35

           x = 35 / 12.22

            x = 2,864 m

This is the distance of observer B

The distance from observer A

            Ra = 35 - x

            Ra = 35 - 2,864

            Ra = 32.1 m

A boxer is punching the heavy bag. The impact of the glove with the bag is 0.10s. The mass of the glove and his hand is 3kg. The velocity of the glove just before impact is 25m/s. What is the average impact force exerted on the glove?

Answers

Answer:

750N

Explanation:

Impulse is the change of momentum of an object when the object is acted upon by a force for an interval of time.

the expression is Ft=mv

where F= force

           m= mass

             t= time

            v= velocity

Step one:

given data

mass m=3kg

velocity v= 25m/s

time t= 0.10seconds

Step two:

we also know that the force on impulse is given as

Ft=mv

F=3*25/0.10

F=75/0.10

F=750N

The magnitude of the average force on the heavy bag if the duration of the collision is 0.1 is 750N

The components of vector Upper A Overscript right-arrow EndScripts are Ax and Ay (both positive), and the angle that it makes with respect to the positive xaxis is θ. Find the angle θ if the components of the displacement vector Upper A Overscript right-arrow EndScripts are:

(a) Ax = 12 m and Ay = 12 m,

(b) Ax= 19 m and Ay = 12 m, and

(c) Ax = 12 m and Ay = 19 m.

(a) θ = Number____________ Units____

(b) θ = Number____________ Units____

(c) θ = Number ____________Units____

Answers

Answer:

(a) θ = 45° = 0.78 rad

(b) θ = 32.27° = 0.56 rad

(c) θ = 57.27° = 1 rad

Explanation:

When a vector is resolved into its rectangular components, the formula for the direction angle of the vector with positive x-axis is given as:

tan θ = Ay/Ax

θ = tan⁻¹(Ay/Ax)

(a)

Ax = 12 m

Ay = 12 m

θ = tan⁻¹(12 m/ 12 m)

θ = tan⁻¹(1)

θ = 45° = 0.78 rad

(b)

Ax = 19 m

Ay = 12 m

θ = tan⁻¹(12 m/19 m)

θ = tan⁻¹(0.6315)

θ = 32.27° = 0.56 rad

(c)

Ax = 12 m

Ay = 19 m

θ = tan⁻¹(19 m/12 m)

θ = tan⁻¹(1.58333)

θ = 57.27° = 1 rad

Air enters into the hollow propeller tube at A with a mass flow of 4 kg/s and exits at the ends B and C with a velocity of 400 m/s, measured relative to the tube. If the tube rotates at 1500 rev/min, determine the frictional torque M on the tube.

Answers

Answer:

643N.m

Explanation:

From this question we have:

Mass flow = 4kg/s

Velocity V = 400m/s

Rotation N = 1500rev/min

We get the relative velocity at exit to be:

V2 = V - r2w

400-0.5x [(2*π*1500)/60]

= 400-78.5

= 321.5m/s

Then we have to calculate the frictional torque My

Mt = Mr2 x V2

= 4x0.5x321.5

= 643Nm

From the calculations above, we get the frictional torque M on the tube to be 643Nm.

A 0.22 caliber handgun fires a 1.9g bullet at a velocity of 765m/s. Calculate the de Broglie wavelength of the bullet. Is the wave nature of matter significant for the bullets?

Answers

Answer:

de Broglie wavelength of the bullet is 4.56 x 10⁻³⁴ mThe value of the wavelength shows that wave nature of matter is insignificant for the bullet because it is larger than particles.

Explanation:

Given;

mass of the bullet, m = 1.9 g = 0.0019 kg

velocity of the bullet, v = 765 m/s

de Broglie wavelength of the bullet is given by;

[tex]\lambda = \frac{h}{mv}[/tex]

where;

h is Planck's constant = 6.626 x 10⁻³⁴ J/s

λ is de Broglie wavelength of the bullet

[tex]\lambda = \frac{h}{mv}\\\\ \lambda =\frac{(6.626*10^{-34})}{(0.0019)(765)}\\\\ \lambda =4.56 *10^{-34} \ m[/tex]

Thus, this value of the wavelength shows that wave nature of matter is insignificant for the bullet because it is larger than particles.

The wavelength will be "[tex]4.56\times 10^{-34} \ m[/tex]".

Given:

Mass, m = 1.9 g or, 0.0019 kgVelocity, v = 765 mPlank's constant, h = 6.626 × 10⁻³⁴ J/s

The De-Broglie wavelength,

→ [tex]\lambda = \frac{h}{mv}[/tex]

By putting the values,

     [tex]= \frac{6.626\times 10^{-34}}{0.0019\times 765}[/tex]

     [tex]= 4.56\times 10^{-34} \ m[/tex]

Thus the response above is right.

Learn more about wavelength here:

https://brainly.com/question/10931065

A crate is pulled due south with a force of 350. N. What other force must be applied if the
net force on the crate is 425 N due north? Enter the magnitude (with units) and direction
(north, south, east, west).

Answers

Answer:

775 N  due North.

Explanation:

If the crate is pulled South with 350 N force, and the net force on the crate results into 425 N due North, then the other force (F) acting must be larger than the 350 N, and pointing North:

F - 350 N = 425 N

F = 425 N + 350 N = 775 N  due North.

Which of the following phrases describes a motor?
A. Changes electrical energy to mechanical energy
B. Never used in appliances with moving parts
C. Can be powered by a hand crank
D. Does not use the interaction between a spinning coil of wire and a
magnet

Answers

Your answer is d I believe

Zinc has a work function of 4.3 eV. a. What is the longest wavelength of light that will release an electron from a zinc surface? b. A 4.7 eV photon strikes the surface and an electron is emitted. What is the maximum possible speed of the electron?

Answers

Answer:

a

[tex]\lambda_{long} = 288.5 \ nm[/tex]

b

The velocity is  [tex]v = 3.7 *0^{5} \ m/s[/tex]

Explanation:

From the question we are told that

   The work function of Zinc is  [tex]W = 4.3 eV[/tex]

Generally the work function can be mathematically represented as

     [tex]E_o = \frac{hc}{\lambda_{long}}[/tex]

=>   [tex]\lambda_{long} = \frac{hc}{E_o}[/tex]

Here  h is the Planck constant with the value  [tex]h = 4.1357 * 10^{-15} eV s[/tex]

  and c is the speed of light with value  [tex]c = 3.0 *10^{8} \ m/s[/tex]

So

     [tex]\lambda_{long} = \frac{4.1357 * 10^{-15} * 3.0 *10^{8}}{4.3}[/tex]

=>  [tex]\lambda_{long} = 2.885 *10^{-7} \ m[/tex]

=>  [tex]\lambda_{long} = 288.5 \ nm[/tex]

Generally the kinetic energy of the emitted electron is mathematically represented as

      [tex]K = E -E_o[/tex]

Here  E is the energy of the photon that strikes the surface

So

    [tex]E- E_o = \frac{1}{2} m * v^2[/tex]

Here m is the mass of electron with value  [tex]m = 9.11*10^{-31 } \ kg[/tex]

Generally  [tex]1 ev = 1.60 *10^{-19} \ J[/tex]

=>   [tex]v = \sqrt{ \frac{2 (E - E_o ) }{ m } }[/tex]

=>    [tex]v = \sqrt{ \frac{2 (4.7 - 4.3 )* 1.60 *10^{-19} }{ 9.11 *10^{-31} } }[/tex]

=>    [tex]v = 3.7 *0^{5} \ m/s[/tex]

   

Simple physics question, check the document. Should take about 3-5 minutes.

Answers

Answer:

The magnitude of the force that the 6.3 kg block exerts on the 4.3 kg block is approximately 41.9 N

Explanation:

Forces on block 4.3 kg are:

63N to the right and R21 (contact force from the 6.3 kg block) to the left

Net force on 4.3 kg block is: 63 N - R21

Forces on the 6.3 kg block are:

R12 to the right (contact force from the 4.3 kg block) and 11 N to the left.

So net force on the 6.3 kg block is: R12 - 11 N

According to the action-reaction principle the contact forces R21 and R12 must be equal in magnitude (let's call them simply "R").

Then, since the blocks are moving with the SAME acceleration, we equal their accelerations:

a1 = (63 N - R)/4.3 = (R - 11 N)/6.3 = a2

solve for R by cross multiplication

6.3 (63 - R) = 4.3 (R - 11)

396.9 - 6.3 R = 4.3 R - 47.3

369.9 + 47.3 = 10.6 R

444.2 = 10.6 R

R = 444.2 / 10.6

R = 41.90 N

when you stir a cup of tea the floating clip collect at the centre of the Cup rather than in the outer Rim why​

Answers

Answer:

hsvshxansjusjsnwjwisks

Explanation:

When we stir a cup of tea we create a force in the center which pulls out all the particles towards it this is the basic reason for collection of tea leaves at the center of the cup rather than at the rim of the cup, it is similar to the the case of tornado where it takes all the particles present on it way to its ..

A 5kg rock is lifted 2m. Find the amount of work done. ​

Answers

Answer:

98J

Explanation:

Given parameters:

Mass of rock  = 5kg

Height = 2m

Unknown:

Work done  = ?

Solution:

The amount of work done is given as:

 Work done  = Force x distance

 Work done = Weight x height

  Work done  = mgH

Now insert the parameters and solve;

 Work done  = 5 x 9.8 x 2 = 98J

The amount of work done on the rock is equal to 98 Nm.

Given the following data:

Mass of rock = 5 kgDistance = 2 meters

To determine the amount of work done:

First of all, we would calculate the force acting on the rock:

[tex]Force = mg\\\\Force = 5 \times 9.8[/tex]

Force = 49 Newton

Now, we can determine the amount of work done:

[tex]Work \;done = force \times distance\\\\Work \;done = 49 \times 2[/tex]

Work done = 98 Nm

Read more: https://brainly.com/question/22599382

A uniform electric field has a magnitude of 10 N/C and is directed upward. A charge brought into the field experiences a force of 50 N downward. The charge must be:_______.

Answers

Answer:

q = 5 C

Explanation:

The electric field is defined as the force experienced by a unit charge when it is brought into the field. Hence, the formula used to find the electrical field is given as follows:

E = F/q

where,

E = Electric Field Magnitude = 10 N/C

F = Force Experienced by the test charge = 50 N

q = Magnitude of the Charge = ?

Therefore,

10 N/C = 50 N/q

q = 50 N/(10 N/C)

Therefore,

q = 5 C

An eraser is thrown upward with an initial velocity of 5.0m/s. The eraser’s velocity after 7.0 second is

Answers

Answer:

-63.6m/s

Explanation:

Given parameters:

Initial velocity  = 5m/s

Time of flight  = 7s

Unknown:

Velocity of the eraser after 7s = ?

Solution:

To solve this problem, we have to use the right motion equation which is given below;

          v  = u - gt

v is the final velocity

u is the initial velocity

g is the acceleration due to gravity  = 9.8m/s²

t is the time taken;

  Now insert the parameters and solve for v;

     v  = 5  - (9.8 x 7)  

    v   = -63.6m/s

If a penny is dropped from rest from a tower takes 2 seconds to hit the ground, how far did it travel?

a 29.4 m
b 19.6 m
с 6.8 m
d 9.8 m​

Answers

Answer:

B

Explanation:

t = 2s

u = 0m/s (released from rest)

a = +g = 9.8m/s²

s = H = ?

using,

s = ut + 1/2at²

H = 0(2) + 1/2(9.8)(2²)

H = 0 + 9.8(2)

s = H = 19.6m

Mr Jones launches an arrow horizontally at a rate of 40m/s off of a 78.4 m cliff towards the south, how far south does the arrow travel. (Step 2, you need the previous questions answer to answer correctly

a. 118.4 m south
b 1936 m south
C 2 m south
d 640 m south​

Answers

Answer:c

Explanation:its the answer because its the answer

Can someone help me with this question

Answers

Answer:

Net force: 20 N to the right

mass of the bag: 20.489 kg

acceleration:  0.976  m/s^2

Explanation:

Since the normal force and the weight are equal in magnitude but opposite in direction, they add up to zero in the vertical direction. In the horizontal direction, the 195 N tension to the right minus the 175 force of friction to the left render a net force towards the right of magnitude:

195 N - 175 N = 20 N

So net force on the bag is 20 N to the right.

The mass of the bag can be found using the value of the weight force: 201 N:

mass = Weight/g = 201 / 9.81 = 20.489 kg

and the acceleration of the bag can be found as the net force divided by the mass we just found:

acceleration = 20 N / 20.489 kg = 0.976  m/s^2

Find the change in thermal energy of a 25kg severed clown doll head that heats up from 25°C to 35°C, and has the specific heat of 1,700 J/(kg°C).

Answers

Answer:

Q = 425 kJ

Explanation:

Given that,

Mass, m = 25 kg

The clown doll head that heats up from 25°C to 35°C

The specific heat is 1700 J/kg°C

We need to find the internal energy of it. The heat required to raise the temperature is given by the formula as follows :

[tex]Q=mc\Delta T\\\\Q=25\times 1700\times (35-25)\\\\Q=425000\ J\\\\Q=425\ kJ[/tex]

So, 425 kJ of thermal energy is severed.

Approximating Venus's atmosphere as a layer of gas 50 km thick, with uniform density 21 kg/m3, calculate the total mass of the atmosphere.Express your answer using two significant figures.m venus atmosphere = ____ kg

Answers

Answer:

m = 4.9 10⁸ kg

Explanation:

The expression for the density is

           ρ = m / V

           m = ρ V

the volume of the atmosphere is the volume of the sphere of the outer layer of the atmosphere minus the volume of the plant

          V = V_atmosphere - V_planet

           V = 4/3 π R_atmosphere³ - 4/3 π R_venus³

           V = 4/3 π (R_atmosphere³ - R_venus³

)

the radius of the planet is R_venus = 6.06 10⁶ m.

The radius of the outermost layer of the atmosphere

          R_atmosphere = 50 10³ + R_ venus = 50 10³ + 6.06 10⁶

           R_atmosphere = 6.11 10⁶ m

let's find the volume

           V = 4/3 pi [(6,11 10⁶)³ - (6,06 10⁶)³]

            V = 23,265 10⁶ m³

let's calculate the mass

          m = 21  23,265 10⁶

          m = 4.89   10⁸ kg

with two significant figurars is

          m = 4.9 10⁸ kg

This is a short question can anyone help me please

Thank you

Picture Above

Answers

Answer:

I thinks it's

deficit spending

Explanation:

cause When a government spends more than it collects in taxes, it is said to have a budget deficit.

The purpose of a motor is to:
A. convert electrical energy to mechanical energy.
B. provide a safe circuit for current flow.
C. convert electrical energy to nuclear energy.
D. convert chemical energy to electrical energy.

Answers

Answer:

a motor is used to covert electrical energy to mechanical energy

A rope is wrapped around the rim of a large uniform solid disk of mass 325 kg and radius 3.00 m. The horizontal disk is made to rotate by pulling on the rope with a constant force of 195 N. If the disk starts from rest, what is its angular speed in rev/s at the end of 2.05 s?

Answers

Answer:

The angular speed is 0.13 rev/s

Explanation:

From the formula

[tex]\tau = I\alpha[/tex]

Where [tex]\tau[/tex] is the torque

[tex]I[/tex] is the moment of inertia

[tex]\alpha[/tex] is the angular acceleration

But, the angular acceleration is given by

[tex]\alpha = \frac{\omega}{t}[/tex]

Where [tex]\omega[/tex] is the angular speed

and [tex]t[/tex] is time

Then, we can write that

[tex]\tau = \frac{I\omega}{t}[/tex]

Hence,

[tex]\omega = \frac{\tau t}{I}[/tex]

Now, to determine the angular speed, we first determine the Torque [tex]\tau[/tex] and the moment of inertia [tex]I[/tex].

Here, The torque is given by,

[tex]\tau = rF[/tex]

Where r is the radius

and F is the force

From the question

r = 3.00 m

F = 195 N

∴ [tex]\tau = 3.00 \times 195[/tex]

[tex]\tau = 585[/tex] Nm

For the moment of inertia,

The moment of inertia of the solid disk is given by

[tex]I = \frac{1}{2}MR^{2}[/tex]

Where M is the mass and

R is the radius

∴[tex]I = \frac{1}{2} \times 325 \times (3.00)^{2}[/tex]

[tex]I = 1462.5[/tex] kgm²

From the question, time t = 2.05 s.

Putting the values into the equation,

[tex]\omega = \frac{\tau t}{I}[/tex]

[tex]\omega = \frac{585 \times 2.05}{1462.5}[/tex]

[tex]\omega = 0.82[/tex] rad/s

Now, we will convert from rad/s to rev/s. To do that, we will divide our answer by 2π

0.82 rad/s = 0.82/2π rev/s

= 0.13 rev/s

Hence, the angular speed is 0.13 rev/s,

Other Questions
The order pairs (1, 2), (2, 5), (3, 10), (4, 17), and (5, 26) represent a function. What is a rule that could represent this function? A. y = x2 + 1 B. y = x2 1 C. y = x2 D. y = x + 1 On what occasion did Henry deliver his Speech in the Virginia Convention?A. many years before the American Revolution began, when tensions first began between the colonies and the BritishB. on the eve of the American Revolution, when the colonists in the north had already begun openly resisting the BritishC. at the midpoint of the American Revolution, when the British were threatening to extend the battle into the southern coloniesD. near the end of the American Revolution, when the colonists in the north were in need of reinforcements and supplies from Virginia What does the narrators description of the wallpaper reveal about the social context of the story? the husbands role as both spouse and physician in the narrators life the narrators feeling that her life is repetitive and meaningless the sister-in-laws daily routine as she observes the narrator the domestic duties of both men and women of the time Guys plz help Answer this QUESTION!!! PLZ HELP OMG!! Ill mark Brainliest to whoever gives correct answer first!!! nWhy do exercise needs vary between individuals?Because you do not want to strain any muscles or tendons. It takes steps to get tothe topI What is the meaning of this quote women have always been courageous... They are always farless when protecting their children and in rge last century they have been fearless in the fight for their rights. The athlete tore down the road in his determination to be first is an example of what figure of speech What is the first step of the following division problem? Mark talked on his cell phone 3 hours over the weekend. Genaro talked on his phone 1 9 10hours. How much longer did Mark talk on his phone than Genaro? A change or addition to the Constitution is known as a(n) _____. aArticle bAmendment cBill dConvention Which option is a compound? PLEASEEEE HELPPPPPPP ASAPPPPP Heyy, I am a 14 year old girl question for girl bossy take my brainliest you want it right Jim opens a CD with $5000 and earns interest at an apt of 5.25%. How much interest would be earned and what would be the balance if he keeps the money in the account for 2 years? help please :))))))))))))))))))))))))))))))))))))))))))))))))))))))))))) Please help!! I need the answer and the explanation on how to do this pb3(po4)2 compound name which of the following was NOT part of schooling in the colonies?