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.

Answer:

Yuh

Explanation:

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

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

Answer:

a) s = 79 m W

b) s = 2 km S

c) s = 250 m W

d) s = 0 km  

Explanation:

We take the following sign convention for the directions:

North (N)  ---> positive

South (S)  ---> negative

East (E) ---> negative

West (W)  ---> positive

a)

45 m W, 34 m W

s = 45 m + 34 m

s = 79 m W

b)

5 km N, 7 km S

s = 5 km - 7 km

s = - 2 km

s = 2 km S

c)

350 m E , 800 m W, 200 m E

s = -350 m + 800 m - 200 m

s = 250 m

s = 250 m W

d)

850 km N, 850 km S

s = 850 km - 850 km

s = 0 km

Answer:

The correct answer will be:

(A) 24955495.07 N/m²

(B) 97482.40 N/m²

Explanation:

(A)

The given values are:

mass,

m = 50 kg

diameter

= 0.50 cm

then,

radius,

r = 0.25 cm

 = 0.0025 m

As we know,

⇒ [tex]A = area \ of \ cross \ section[/tex]

       [tex]=\pi r^2[/tex]

and,

⇒ [tex]stress = \frac{mg}{A}[/tex]

On substituting the values, we get

              [tex]=\frac{(50)(9.8)}{\pi (0.0025^2)}[/tex]

              [tex]=24955495.07 \ N/m^2[/tex]

(B)

mass,

m = 5000 kg

radius,

r = 20 cm

 = 0.2 m

Now,

⇒ [tex]stress=\frac{\frac{5000}{4} (9.8)}{\pi (0.2^2)}[/tex]

              [tex]=97482.40 \ N/m^2[/tex]

Answer:

a

Explanation:

..................

Answer:

Force = 49N

Explanation:

Force is given by the multiplication of mass and acceleration.

Mathematically, Force is;

[tex] F = ma[/tex]

Where;

F represents force measured in Newton.

m represents the mass of an object measured in kilograms.

a represents acceleration measured in meter per seconds square.

Given the following data

Mass = 5kg

We know that acceleration due to gravity = 9.8m/s²

To find the Force:

[tex] F = 5*9.8 [/tex]

Force = 49N

Answer:10.m and 10. M

Explanation:

A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.

A displacement vector with a magnitude of 20. meters can be decomposed in 2 perpendicular components.

They would form a right triangle, in which the displacement vector would be the hypotenuse (a) and the components would be the legs (b, c).

Given the magnitude of the legs, we can calculate the magnitude of the hypotenuse using the Pythagorean theorem.

[tex]c = \sqrt{a^{2} + b^{2} }[/tex]

Let's use this formula to calculate the displacement vector for each pair of legs.

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(10.m)^{2} + (10.m)^{2} }= 14.1m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (8.0m)^{2} }= 14.4m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(12m)^{2} + (16m)^{2} }= 20m[/tex]

[tex]c = \sqrt{a^{2} + b^{2} } = \sqrt{(16m)^{2} + (8.0m)^{2} }= 17.9m[/tex]

A displacement vector with a magnitude of 20. m could have perpendicular components with magnitudes of C. 12 m and 16 m.

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Answer:

Thermal energy

Explanation:

The internal energy of a system is widely known as thermal energy. Now, thermal energy is also called heat energy and it is an internal energy of a component which is produced when an increase in temperature causes atoms and molecules within the component to move faster and start colliding with one other.

Therefore, the more heat the is applied to the component, the hotter the substance and the more its particles move which in turn leads to a higher thermal energy.

Answer:

54 s

Explanation:

Given that,

Mass of a car, m = 15000 kg

Initial speed, u = 5.4 m/s

Final speed, v = 0 (it comes to rest)

Force, F = 1500 N

We need to find time when it comes to rest. Let it is t. Net force is given by :

F = ma, a is acceleration of the car

[tex]F=\dfrac{m(v-u)}{t}\\\\t=\dfrac{m(v-u)}{F}\\\\t=\dfrac{15000\times (0-5.4)}{1500}\\\\t=54\ s[/tex]

So, it will take 54 seconds to come to rest.

The time required to bring the car to rest is 54 s and the right option is (b) 54 s.

To calculate the time required for the force to bring the car to rest, we use the formula below.

Formula:

Where:

Make t the subject of the equation

From the question,

Given:

Substitute these values into equation 2

Hence, The time required to bring the car to rest is 54 s and the right option is (b) 54 s.

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Answer:

Explanation:

According to newtons second law of motion;

F = ma .... 1

Also the force acting aong the inclines is expressed as;

F = mgsintheta

m is the mass of the object

a is the acceleration

theta is angle of inclination

Equate 1 and 2

ma = mg sin theta

a = gsin(theta)

a = 9.8sin30

a = 9.8(0.5)

a = 4.9m/s²

Hence the acceleration of the ping pong is 4.9m/s²

Answer:

Newton's theory because he suggested that the greater the distance between objects, the weaker the pull of gravity.

Answer: The answer is Newton’s theory because he suggested that the greater the distance between objects, the weaker the pull of gravity

Explanation: Just took the test i hope this help you enjoy :D

Answer:

B. Sound waves will not be transformed into electrical signals.

Explanation:

edge2021

Sound waves will not be transformed into electrical signals is the reason that microphone on an AM radio is not working properly.

It is a type of mechanical wave composed of the disturbance caused by the movements of the energy. A sound wave travels through compression and rarefaction in an elastic medium such as air.

The microphone on an AM radio is not working properly means sound waves are not transforming into electrical signals.

Learn more about sound waves

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Answer: Givens

a = 4.4 m/s^2 This is an acceleration and is positive.

vi = 10.2 m/s

t = 4.2 seconds

vf = ????? The cruising speed in this case is vf.

Formula

a = (vf - vi)/t Notice the 3 givens and what you seek determine the formula

Solve

4.4 m/s^2 = (vf - 10.2)/4.2 Multiply both sides by 4.2

4.4 * 4.2 = vf - 10.2

18.48 = vf - 10.2 Add 10.2 to both sides

18.48 + 10.2 = vf 8.28 is the second best answer.

28.68 = vf This is your cruising speed.

C <<<< Answer

7.62 (2dp)

Explanation:

U = 0m/s

V = 32m/s

A = 4.2m/s^2

T = ?

[tex]a = \frac{v - u}{t}[/tex]

[tex]t = \frac{v - u}{a} [/tex]

[tex]t = \frac{32 - 0}{4.2} [/tex]

[tex]t = \frac{32}{4.2} [/tex]

[tex]t = 7.62 \: (2dp)[/tex]

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Answer:

a = 0.5 [m/s²]

Explanation:

To solve this problem we must use Newton's second law which tells us that the sum of forces is equal to the product of mass by acceleration.

ΣF = m*a

F = force = 200 [N]

m = mass = 400 [kg]

a = acceleration [m/s²]

Now replacing:

200 = 400*a

a = 0.5 [m/s²]

Answer:

6.56km

Explanation:

Given parameters:

Speed  = 11.5km/hr

Time  = 2060s

Unknown:

Distance covered  = ?

Solution:

Speed is distance divided by the time taken.

   Speed  = [tex]\frac{distance}{time}[/tex]

   Distance  = Speed x time

Let us convert the seconds to hours;

      3600s  = 1hr

      2060s = [tex]\frac{2060}{3600}[/tex]   = 0.57hr

Now

 Distance  = 11.5km/hr x 0.57hr  = 6.56km

Answer:

8) 709.8875 J

9) The object is at 7.24375 m from the ground

10) Kinetic energy increases as the object falls.

Explanation:

We use the expression for the displacement h(t) as a function of time of an object experiencing free fall:

h(t) = hi - (g/2) t^2

hi being the initial position of the object (10m) above ground, g the acceleration of gravity (9.8 m/s^2), and t the time (in our case 0.75 seconds):

h(0.75) = 10 - 4/9 (0.75)^2 = 7.24375 m

This is the position of the 10 kg object after 0.75 seconds (answer for part 9)

Knowing this position we can calculate the potential energy of the object when it is at this height, using the formula:

U = m g h = 10kg * 9.8 (m/s^2) * 7.24375 m = 709.8875 J (answer for part 8)

Part 10)

the kinetic energy of the object increases as it gets closer to ground, since its velocity is increasing in magnitude because is being accelerated in its motion downwards.

Answer:

5N

Explanation:

Given parameters:

Original length = 22cm

Spring constant, K  = 50N/m

New length = 32cm

Unknown

Force applied  = ?

Solution:

The force applied on a spring can be derived using the expression below;

   Force  = KE

 k is the spring constant

 E is the extension

  extension = new length - original length

  extension  = 32cm  - 22cm  = 10cm

convert the extension from cm to m;  

   100cm  = 1m;

    10cm will give 0.1m

So;

  Force  = 50N/m x 0.1m  = 5N

Answer:

F = 5.4 x 10⁻⁸ N

Explanation:

The gravitational force of attraction between two objects is given by Newton's Gravitational Law as follows:

F = Gm₁m₂/r²

where,

F = Gravitational Force = ?

G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²

m₁ = mass of student = 92 kg

m₂ = mass of pizza slice = 550 g = 0.55 kg

r = distance between student and pizza slice = 25 cm = 0.25 m

Therefore,

F = (6.67 x 10⁻¹¹ N.m²/kg²)(92 kg)(0.55 kg)/(0.25 m)²

F = 5.4 x 10⁻⁸ N

Answer:no sure sorry

Explanation:

Answer:

Explanation:

Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification. The cartilage in the region of the epiphyseal plate next to the epiphysis continues to grow by mitosis. The chondrocytes, in the region next to the diaphysis, age and degenerate.

Answer:

The magnetic field is [tex]B = 2.319 *10^{-3} \ T[/tex]

Explanation:

From the question we are told that

   The radius of the wire is [tex]r = 0.8 \ cm = 0.008 \ m[/tex]

    The current is [tex]I = 106 \ A[/tex]

    The position considered is  d = 0.07 cm = 0.0007 m

 Generally the magnetic field is mathematically represented as

         [tex]B = \frac{\mu_o * I}{2\pi * \frac{r^2}{d} }[/tex]

Here [tex]\mu_o[/tex] is the permeability of free space with value [tex] 4\pi * 10^{-7} N/A^2[/tex]

So    

        [tex]B = \frac{ 4\pi * 10^{-7} * 106 }{2 * 3.142 * \frac{0.008^2}{0.0007} }[/tex]

=>     [tex]B = 2.319 *10^{-3} \ T[/tex]

Answer:

I'm pretty sure its c

Hope you get a good grade-

Answer:

sry i need points

Explanation:

Answer:

1750Nm/s

Explanation:

70*25=1750Nm/s

Answer:

1750 kgm/s

Explanation:

The equation for momentum is p = mv = 70 * 25 = 1750

Answer:

Reverse check the answer

Explanation:

I believe it is very important that once someone is done with any calculation, the person ought to go over the calculations again. And even, recheck the answer in inverted form.

This is so because while doing the calculations, we can possibly make errors that we won't notice until after submission. Knowing 2 * 3 = 6, but writing 2 * 3 = 5 in the course of calculations can happen to anybody. So therefore, cross checking and reverse checking is needed

Answer:

0.56rad/s²

Explanation:

Using the equation of motion

wf = wi + αt

wf is the final angular velocity

wi is the initial angular velocity

α is the angular acceleration

t is the time

Given

wf = 11.0rad/s

wi =2.0rad/s

t = 5.5secs

Substitute into the formula and get α

11.0 = 2.0+5α

11.0-2.0 = 5α

9.0 = 5α

α = 5/9.0

α ≈ 0.56rad/s²

Hence the wheel's average angular acceleration is 0.56rad/s²

The wheel's average angular acceleration is equal to 1.64 [tex]rad/s^2[/tex].

Given the following data:

To determine the wheel's average angular acceleration, we would apply the first equation of kinematics:

Mathematically, the angular acceleration of an object is given by the formula:

[tex]\alpha = \frac{\omega_f - \omega_i}{t}[/tex]

Where:

Substituting the given parameters into the formula, we have;

[tex]\alpha =\frac{11.0\;-\;2.0}{5.5} \\\\\alpha =\frac{9.0}{5.5}[/tex]

Angular acceleration = 1.64 [tex]rad/s^2[/tex]

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Answer:

The position of the person's feet. a running shoe company studying how different surfaces affect the life of a shoe tread

Explanation:

100%

Answer:

1. The position of the person's feet.

2. A running shoe company studying how different surfaces affect the life of a shoe tread

Explanation:

100% correct

Answer:

Speed = 100 km/h

Explanation:

Given:

Speedometer reading = 100 kph for one lap

Assume;

Time taken to complete one lap = 1 hour

Computation:

Speed =  Distance / Time

Speed =  100 / 1

Speed = 100 km/h

Answer:

5707 m/s^2

Explanation: