Which of the following best describes the upper respiratory tract?
O It takes air in from outside the body.
O It is where oxygen and carbon dioxide are exchanged.
O It is located inside the thorax.
O It is not directly involved in respiration.

Answer:

3.73 * 10^16   photons/sec

Explanation:

power supply = 3.0 V

Emits 440 nm blue light

current in LED = 11 mA

efficiency of LED = 51%

Calculate the number of photons per second the LED will emit

first step : calculate the energy of the Photon

E = hc / λ

   =(  6.62 * 10^-34 * 3 * 10^8 )  / 440 * 10^-9

   = 0.0451 * 10^-17  J

Next :

Number of Photon =( power supply * efficiency * current ) / energy of photon

= ( 3 * 0.51 * 11 * 10^-3 ) / 0.0451 * 10^-17

= 3.73 * 10^16 photons/sec

Answer:

B. The Spring equinox

Explanation:

The vernal equinox marks the moment the sun crosses the celestial equator.  The vernal equinox happens on March 19, 20, or 21 every year in the Northern Hemisphere. In the Southern Hemisphere, this same event marks the beginning of fall.  (Source: What Exactly Is The Spring Equinox? - Dictionary.com)

Hopefully this helps.

Answer:

1. 0.625 g/mL

2. 2×10⁵ J

3. 5040 J

4. 75000 J

Explanation:

1. Determination of the density.

We'll begin by calculating the volume of the marble. This can be obtained as follow:

Volume of water = 60 mL

Volume of water + Marble = 68 mL

Volume of marble =?

Volume of marble = (Volume of water + Marble) – (Volume of water)

Volume of marble = 68 – 60

Volume of marble = 8 mL

Finally, we shall determine the density of the marble. This can be obtained as follow:

Mass of marble = 5 g

Volume of marble = 8 mL

Density of marble =?

Density = mass / volume

Density of marble = 5 / 8

Density of marble = 0.625 g/mL

2. Determination of the work done.

Mass (m) = 1000 Kg

Height (h) = 20 m

Acceleration due to gravity (g) = 10 m/s²

Workdone (Wd) =?

The work done can be obtained as follow:

Wd = mgh

Wd = 1000 × 10 × 20

Wd= 2×10⁵ J

3. Determination of the potential energy.

Mass (m) = 12 Kg

Height (h) = 42 m

Acceleration due to gravity (g) = 10 m/s²

Potential energy (PE) =?

The potential energy can be obtained as follow:

PE = mgh

PE = 12 × 10 × 42

PE = 5040 J

4. Determination of the kinetic energy.

Mass (m) = 1500 Kg

Velocity (v) = 10 m/s

Kinetic energy (KE) =?

The kinetic energy can be obtained as follow:

KE = ½mv²

KE = ½ × 1500 × 10²

KE = 750 × 100

KE = 75000 J

Answer:

W = 354.9 J

Explanation:

Given that,

The mass of a bale of hay, m = 23 kg

The displacement, d = 3.9 m

The horizontal force exerted on the hay, F = 91 N

We need to find the work done. We know that,

We know that,

Work done, W = Fd

So,

W = 91 N × 3.9 m

W = 354.9 J

So, the required work done is 354.9 J.

Its angular momentum of a satellite will drop even as satellite panel stretch because of the reduction in angular velocity brought on by the drag effect.

A portion of the star's mass is blown off during the supernovae that come before the creation of black holes, taking some of the star's total angular momentum with it.The leftover material sinks into the star's core while continuing to spin rapidly.

Magnus effect: When there is relative movement between both the spinning item and the fluid, a sideways force is generated on a rotating cylindrical or spherical object immersed in the fluid (liquid or gas).In honor of the German chemist and physicist H.G.

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Answer:

0.035 J

Explanation:

Applying,

W = ke²/2.............. Equation 1

Where W = workdone by the stretching the spring, k = spring constant, e = extension.

make k the subject of the equation

k = 2W/e²............... Equation 2

From the question

Given: W = 2 J, e = (43-28) = 15 cm = 0.15 m

Substitute these values into equation 2

k = (2×2)/(0.15²)

k = 177.78 N/m

Hence, work need to stretch the spring from 33 cm to 35 cm

therefore,

e = 35-33 = 2 cm = 0.02 m

Substitute into equation 1

W = 177.78(0.02²)/2

W = 0.035 J

Explanation:

heat caoacity and heat is difference

The heat energy conducted per hour through the side walls of the cylindrical steel boiler  is 27708847 kJ.

The rate at which heat is transported by conduction through a material's unit cross-section area when a temperature gradient exits perpendicular to the area is known as thermal conductivity.

In the International System of Units (SI), thermal conductivity is measured by Wm⁻¹K⁻¹.

Diameter of the cylindrical steel boiler: d = 1.00m.

Length  of the cylindrical steel boiler: l = 3.00m.

thickness of the walls is = 6.0 mm = 0.006 m

Temperature gradient is = (140-40) °C/0.006 m = 1666.67 °C/m

Thermal conductivity of steel,  = 42 W/m-°C.

Hence, the heat energy conducted per hour through the side walls of the cylindrical steel boiler = 42×3600×1666.67 ×2π×0.5(0.5+3.0) Joule

= 27708847 kJ

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Answer:

Magnitude = 15.86 units

direction = 69 degree below negative X axis

Explanation:

A = 20 units at 60.0° counterclockwise from the negative x - axis

B = 40 units at 30.0° counterclockwise from the positive x - axis

C = 35 units at 60.0° clockwise from the negative y - axis

Write the vectors in the vector form

[tex]\overrightarrow{A} =20 (- cos 60 \widehat{i} - sin 60 \widehat{j})=- 10\widehat{i} - 17.3 \widehat{j}\\\\\overrightarrow{B} =40 (cos 30 \widehat{i} + sin 30 \widehat{j})= 34.6\widehat{i} +20 \widehat{j}\\\\\overrightarrow{C} =35 (- sin 60 \widehat{i} - cos 60 \widehat{j})=- 30.3\widehat{i} - 17.5 \widehat{j}\\\\Now\\\\overrightarrow{A} + \overrightarrow{B} + \overrightarrow{C} = (- 10 + 34.6 - 30.3) \widehat{i} + (-17.3 + 20-17.5)\widehat{j}\\\\[/tex]

[tex]\\\overrightarrow{A} + \overrightarrow{B} + \overrightarrow{C} = - 5.7\widehat{i} -14.8\widehat{j}[/tex]

The magnitude is given by

[tex]= \sqrt{5.7^2 + 14.8^2} = 15.86 units[/tex]

The direction is given by

[tex]tan\theta = \frac{- 14.8}{- 5.7}\\\\\theta= 69^o[/tex]

below negative X axis.  

Answer:

10.66 m/s

Explanation:

Applying,

The law of conservation of momentum,

Total momentum before collision = Total momentum after collision

mu+m'u' = V(m+m').............. Equation 1

Where m = mass of the first puck, u = initial velocity of the first puck, m' = mass of the second puck, u' = initial velocity of the second puck, V = Velocity of the center of the two pucks

make V the subject of the equation

V = (mu+m'u')/(m+m').............. Equation 2

Given: m = 0.18 kg, u = 16 m/s, m' = 0.14 kg, u' = 3.8 m/s

Substitute these values into equation 2

V = [(0.18×16)+(0.14×3.8)]/(0.18+0.14)

V = (2.88+0.532)/(0.32)

V = 3.412/0.32

V = 10.66 m/s

Answer:

B) Blackbody radiation

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Answer:

Black body radiation

Explanation:

Answer:

D) 1.5032 x 10^-10 J

Explanation:

The rest energy of a proton, E₀, follows the equation:

E₀ = mp*rate²

Where mass of proton, mp = 1.6726 x 10^-27kg

rate = 2.9979 x 10^8 m/s (2.9979 x 10^9 m/s is not the speed light)

E₀ = 1.6726 x 10^-27kg * (2.9979 x 10^8 m/s)²

E₀ =1.5032 x 10^-10 J

Right answer is:

Answer:

the ratio Bonzo/mEnder of the masses of these two enemies is 3.91

Explanation:

Given the data in the question;

Velocity of Bonzo [tex]V_{Bonzo[/tex] = 1.1 m/s

Velocity of Ender [tex]V_{Ender[/tex] = -4.3 m/s

the ratio Bonzo/mEnder of the masses of these two enemies = ?

Now, using the law of conservation of momentum.

momentum of both Bonzo and Ender are conserved

so

Initial momentum = final momentum

we have

0 = [tex]m_{Bonzo[/tex] × [tex]V_{Bonzo[/tex] + [tex]m_{Ender[/tex] × [tex]V_{Ender[/tex]

[tex]m_{Bonzo[/tex] × [tex]V_{Bonzo[/tex] = -[ [tex]m_{Ender[/tex] × [tex]V_{Ender[/tex]  ]

[tex]m_{Bonzo[/tex] / [tex]m_{Ender[/tex]  = -[ [tex]V_{Ender[/tex] / [tex]V_{Bonzo[/tex] ]

we substitute

[tex]m_{Bonzo[/tex] / [tex]m_{Ender[/tex]  = -[ -4.3 m/s / 1.1 m/s ]

[tex]m_{Bonzo[/tex] / [tex]m_{Ender[/tex]  = -[ -3.9090 ]

[tex]m_{Bonzo[/tex] / [tex]m_{Ender[/tex]  = 3.91

Therefore, the ratio Bonzo/mEnder of the masses of these two enemies is 3.91

Answer:

dislike of or prejudice against people from other countries.

Explanation:

Answer: dislike of or prejudice against people from other countries.

Explanation:

Explanation:

Total voltage = 9 × 2 = 18v

Resistance = 82 Ω

Ohm's law::

V = IR

18v = 82 Ω × I

18v /82 /Ω = I

18/82 Ampere is the current

Answer:

the area of the rectangular field is 10.5 m²

Explanation:

Given;

length of the rectangular field, L = 42 cm = 0.42 m

breadth of the rectangular field, b = 25 m

The area of the rectangular field is calculated as follows;

Area = Length x breadth

Area = 0.42 m x 25 m

Area = 10.5 m²

Therefore, the area of the rectangular field is 10.5 m²

Answer:

a. 50km/hr.

b. 10km/hr

Explanation:

Average speed, which is calculated by dividing the total distance travelled by the time interval as follows:

Average speed = total distance travelled ÷ time

Average velocity is calculated by dividing the total displacement by the time interval as follows:

Average velocity = change in displacement (∆x) ÷ time (t)

According to this question, a motorist travels due North at 90 km/h for 2 hours. She then changes direction and travels West at 60 km/for 1 hour.

Total distance of this journey is 90 + 60 = 150

Total time taken = 1 + 2 = 3hours

Average speed = 150/3

= 50km/hr.

b.) Average velocity = x2 - x1/t

Average velocity = 90 - 60/3

= 30/3

= 10km/hr

Answer:

171.5 m

Explanation:

To find the distance, speed x time

342 x 0.5

171.5 m

Hope this helped!

Answer:

sorry I don't know I am only in 7th grade

Answer:

1. Power = 5000 Watts

2. Workdone = 11185.5 Joules

Explanation:

Given the following data;

1. Distance = 18 m

Energy = 100 KJ = 100,000 Joules

Time = 20 seconds

To find the average power of the elevator;

Power = energy/time

Power = 100000/20

Power = 5000 Watts

2. Power = 0.4 HP

Time = 15 seconds

Conversion:

1 horsepower = 745.7 Watts

0.4 horsepower = 0.4 * 745.7 = 298.28 Watts

To find the amount of work done by the electric mixer;

Work done = power * time

Workdone = 745.7 * 15

Workdone = 11185.5 Joules

Answer:

D because of POE

Explanation:

the reaction force is the ball exerting the same newtons of force back to your leg opposite of the ball, but the reaction force and the action force is never stronger than each-other. and action is only being done on the soccer ball, so process of elimination, the answer is D

Answer:

B

Explanation:

it can only have a different motion if it is acted upon a different ball

Answer:

The two important factors that affect heat energy are specific heat and temperature. Specific heat is a heat-constant of a material per unit mass per degree of temperature change (in units of energy per mass and temperature), like Joules/Kg-°C .

Thank you.....

Have a good day.....

Answer:

A charge is a physical entity that has been quantized. The limits on its values are the value of a charged particle quantized in the state where 'n'...

Explanation:

One example of a physical entity that is quantized is:

The amount of money in your pocket.

The amount can't have any fraction of 1 cent.  

Its value must be an integer-multiple of cents, or 0.01 dollar.    

When it increases or decreases, it jumps from one integer number of cents to the next integer number.  It doesn't "slide" from one to the next.  It can never have a value between two integer numbers of cents.

Answer:

3.92N

Explanation:

Force= mass×accelerarion due gravity

But mass= 0.40kg

acceleration due to gravity = 9.8 m/s^2

Force = 0.40×9.8

Force=3.92N

Explanation:

Much greater. Gravitational force depends on the mass and separation distance. Shrinking the earth means the mass remains the same while the radius gets smaller. Since gravitational force is inversely proportional to the square of the separation distance, as shown by Newton's universal gravitational law

[tex]\:\:\:F_G = G \dfrac{mM_E}{R^2}[/tex]

shrinking the radius even by a factor of 10 will cause your weight, which also happens to be the gravitational force of the earth on you, to be 100 times more.

If the mass of the Earth remains the same and only its volume and radius are decreased, then the average density of the Earth would increase significantly.

Gravity, also known as gravitational force, pulls objects with mass towards each other. We frequently consider the force of gravity from Earth.

If the Earth's mass remains constant while its volume and radius are reduced, the average density of the Earth increases significantly.

This is due to the fact that the mass has been compressed into a much smaller volume.

As a result, standing on the surface, the gravitational force on you would be greater than before the Earth was compressed to the size of a small mountain.

When the Earth is compressed, the distance between you and the center of the Earth decreases while the mass remains constant.

Thus, your gravitational force increases.

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Answer:

The average power per day is 1008 kW.

Explanation:

Solar constant = 1.4 kW/m2

efficiency = 20 %

area, a = 1 square meter

time = 6 hours

Energy falling on the panel in 6 hours = 1.4 x 6 x 3600 kJ

The output is

= 20 % of 1.4 x 6 x 3600

= 0.2 x 1.4 x 6 x 3600

= 6048 kJ

Average power per day is

= 6048/6 = 1008 kW

The time required to lift the weight is 5 seconds.

Time is the measure of past or present events or occurrences. The S.I unit of time is seconds (s).

To calculate the time required to lift the weight, 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 lift the weight is 5 seconds.

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Answer:

the sun

Explanation:

The sun is the source of almost all energy on Earth beacuse both plants and animal on Earth derive their energy from the sun.

The Earth is one of the planets that make up the solar system. The Sun is the center of the universe and the Earth revolves round the sun.

The source of almost all energy on Earth is from the sun. The energy from the sun is callled solar energy.

This energy from the sun can be used by the planet to manufatcure its own food. The plants are consumed by animals to provide energy their metabolic activities.

Thus, we can conclude that the sun is the source of almost all energy on Earth beacuse both plants and animal on Earth derive their energy from the sun.

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Answer:

The correct answer will be "0.25 sec".

Explanation:

The graph of the given question is attached below.

According to the graph of the question,

Time,

T = 1 sec

For the upward velocity,

⇒ [tex]t = \frac{T}{4}[/tex]

By putting the value, we get

⇒    [tex]=\frac{1}{4}[/tex]

⇒    [tex]=0.25 \ sec[/tex]

This question is incomplete, the complete question is;

In June 1985, a laser beam was sent out from the Air Force Optical Station on Maui and reflected back from the shuttle Discovery as it passed by 354 km overhead. The diameter of the central maximum of the beam at the shuttle position was said to be 9.1 m, and the beam wavelength was 500 nm.

What is the effective diameter of the circular laser aperture at the Maui ground station

Answer:

the effective diameter of the circular laser aperture at the Maui ground station is 4.747 cm

Explanation:

Given the data in the question;

Separation between observer and point L = 354 km = 354000 m

Linear separation D = 9.1 m

wavelength λ = 500 nm = 500 × 10⁻⁹ m

Now, for small angles;

θ = D / L

θ = 9.1 m /  354000 m

θ = 2.57 × 10⁻⁵ rad

For a circular aperture;

sinθ = ( 1.22 × λ ) / d

for small angles;

θ = ( 1.22 × λ ) / d

so

θ = 2 × θ

θ = 2 × [( 1.22 × λ ) / d]

we substitute

2.57 × 10⁻⁵ = 2 × [( 1.22 × 500 × 10⁻⁹ ) / d]

2.57 × 10⁻⁵ = 0.00000122 / d

d = 0.00000122 / 2.57 × 10⁻⁵

d = 0.04747 m

d = ( 0.04747 × 100 )m

d = 4.747 cm

Therefore, the effective diameter of the circular laser aperture at the Maui ground station is 4.747 cm

Answer:

Capacitance= 1.18×10^-6

Answer: 1.18*10^-6

Explanation: