numerical study on transient airflows and air exchange induced by door motion in thermally stratified environment

Answer:

electric

please give brainliest

The average speed of person is  21.87 m/s.

Given data:

The first 100 m distance is covered in 5 minutes.

Next, 200 m distance is covered in 7 minutes.

And finally, the distance of 50 m is covered in 4 minutes.

The average speed of any object is defined as the total distance covered by object in an entire journey divided by the total time taken to cover the journey. The mathematical expression for the average speed of person is,

\(v_{av.}=\dfrac{D_{total}}{t_{total}}\\\\\\v_{av.}=\dfrac{100 +200+50}{5+7+4}\\\\\\v_{av.}=21.87 \;\rm m/min\)

Thus, we can conclude that the average speed of person is  21.87 m/min.

Learn more about the average speed here:

https://brainly.com/question/12322912

The answer to your question is (c): each point of a light-emitting object sends an infinite number of rays. This is because light is a form of electromagnetic radiation that is emitted in all directions from a source.

Each point on an object emits light in all directions, meaning that an infinite number of rays are sent out from each point. This is why we can see objects from different angles and perspectives - because light is being emitted in all directions from each point on the object.

However, it's important to note that not all of these rays will necessarily reach our eyes, as they can be blocked or scattered by other objects in the environment.

To know more about light-emitting visit:-

https://brainly.com/question/28163524

#SPJ11

Answer:

chenged when not anet force

The length of its sides in kilometers is \(0.000290 km\)

What is celestial mechanics?

Celestial mechanics is a scientific discipline that studies the motion and behavior of celestial bodies, including planets, moons, asteroids, comets, and stars, using principles and laws of physics. It focuses on understanding the gravitational interactions between celestial objects and how they influence their orbits, positions, and movements in space.

\(\textbf{(a) Pressure Calculation:}\)

To find the pressure, we can use the ideal gas law equation, which states:

\(\[ PV = nRT, \]\)

where \($P$\) is the pressure, \($V$\) is the volume, \($n$\) is the number of moles of gas, \($R$\) is the gas constant and \($T$\) is the temperature.

In this case, the number of moles (\($n$\)) is given as 1 mol, the gas constant (\($R$\)) is a known value, and the temperature (\($T$\)) is given as \(2.7 K\). However, we need to determine the volume (\($V$\)) in order to calculate the pressure.

\(\textbf{(b) Volume Calculation:}\)

The volume occupied by 1 mol of gas can be calculated using Avogadro's Law, which states that equal volumes of gases at the same temperature and pressure contain an equal number of particles. One mole of any gas at standard temperature and pressure (STP) occupies a volume of 22.4 liters

\((22.4 L) \\or\\ 0.0224 cubic meters (0.0224 m$^3$).\)

\(\textbf{(c) Length Calculation:}\)

If the volume is a cube, and we know the volume is \(0.0224 m$^3$\), we can calculate the length of its sides by taking the cube root of the volume. Therefore, the length of each side is:

\(\[ \text{Length} = \sqrt[3]{\text{Volume}} = \sqrt[3]{0.0224} \approx 0.290 \, \text{m}.\]\)

To convert this length to kilometers, we divide by 1000:

\(\[ \text{Length in kilometers} = \frac{0.290 \, \text{m}}{1000} = 0.000290 \, \text{km}.\]\)

Therefore, the length of its sides in kilometers is \(0.000290 km\)

Learn more about celestial mechanics:

https://brainly.com/question/30421407

#SPJ4

Answer:

The mass of the block of material is 3 x 10³⁷ g/mol

The charge of the material is  4.8 x 10⁸ C

Explanation:

Given;

number of protons of the material, P = 3 x 10²⁷

number of neutrons in the material, N = 3 x 10³⁷

number of electrons in the material, E =  3 x 10²⁷

The mass of the block of material is calculated as follows;

M = P + N

M =  3 x 10²⁷ +  3 x 10³⁷

M =  3 x 10³⁷ g/mol

The charge of the material is calculated as follows;

charge of 1 electron = 1.6 x 10⁻¹⁹ C

charge of  3 x 10²⁷ electrons =  3 x 10²⁷ electrons   x   1.6 x 10⁻¹⁹ C

                                                = 4.8 x 10⁸ C

Answer:

360 degrees is one full rotation starting at zero

it take 2 s  to the flag to rotate once in a full circle  with 3 rad/s of angular velocity.

Angular velocity is "rate of change of angular displacement with respect to time". i.e. ω= dθ/dt. it is also defined as angular displacement over time. i.e. ω = angular displacement/Time.

Angular velocity shows how much angle can be covered in unit time. It's SI unit rad/s.

Angular acceleration is rate of change of Angular velocity with respect to time.

i.e. α = dω/dt if an object changes its angular velocity in short time, we can say that it has greater angular acceleration. It is expressed in rad/s².

In this problem we have to calculate time, but the angular velocity id not given.

Consider the angular velocity is 3 rad/s.

Given,

Angular displacement θ = 2π

angular velocity ω = 3 rad/s

Time t = ?

Time = θ/ω

Time = 2π/3 rad/s = 2 s

Hence the answer is 2s.

To know more about angular velocity :

https://brainly.com/question/29557272

#SPJ2.

Answer:

1. While boiling replace the cap and allow it to cool. Vapours inside condense and form water creating vacuum above them. Observation - The can crumbles due to air pressure from outside. This proves that air exerts pressure.

2. Measure the volume of the liquid displaced when the object is submerged. Measure the initial volume of water in graduated cylinder. Submerge the irregular object. Measure the final volume of the water.

— The difference between the initial volume and the final volume is the volume of the object.

hope can help ^_^

The amount work done by the monster is 4176 J.

Work is said to be done when a force moves an object through a distance.

To calculate the work done by the monster,  we use the formula below

Formula:

Where:

From the question,

Given:

Susbtitute these values into equation 1

Hence, the work done is 4176 J.

Learn morea about work done here: https://brainly.com/question/25573309

#SPJ1

Answer:

\(m_B > m_A\)

the mass of body B must be greater than the mass of body A

Explanation:

Newton's second law establishes a linear relationship between the force, the mass of the body and its acceleration

        F = m a

        a = F / m

Let's analyze this expression tells us that the force is of equal magnitude for the two bodies, but body A goes faster than body B, this implies that it has more relationships

         a_A > a_B

         \(\frac{F}{m_A} > \frac{F}{m_B}\)

         \(m_B > m_A\)

Therefore, for this to happen, the mass of body B must be greater than the mass of body A

Answer:

The velocity of the stone is 2.57 m/s.

Explanation:

Given that

Height = 0.337 m

We need to calculate the velocity of the stone

Using equation of motion

\(v^2-u^2=2gh\)

Where, v = velocity of stone

u = initial velocity

g = acceleration due to gravity

h = height

Put the value into the formula

\(v^2-0=2\times9.8\times 0.337\)

\(v=\sqrt{2\times9.8\times0.337}\)

\(v=2.57\ m/s\)

Hence, The velocity of the stone is 2.57 m/s.

Given,

The mass of the car, m=1000 kg

The velocity of the car, v=20 m/s

The kinetic energy of an object is the energy of the body possessed due to its motion. The kinetic energy of a body is directly proportional to the square of the velocity of the object.

The kinetic energy of the car is given by,

On substituting the known values,

Thus the kinetic energy of the given car is 200 kJ.

Answer:

1.27551m

Explanation:

This is a simple energy convertion problem. Since there is no friction, and assuming no air drag and other external factors, mechanical energy should be conserved in this system.

Thus, we get:

\(KE_{initial} + PE_{initial} = KE_{final} + PE_{final}\)

We also know that the gravitational potential energy is equal to mgh, while the KE can be calculated using \(\frac{1}{2}mv^2\)

One thing to note here, is that the final KE will be 0, as there is no velocity at the end. Furthermore, we also can set the initial PE as 0 as we are looking at relative height, and at the start it is at h=0.

\(KE_{initial} = PE_{final}\)

Plugging in:

\(\frac{1}{2}*30*5^2 = 30*9.8*h\)

Solving for h, we get 1.27551m

I think its c

d a c b

I hope this is helpful

Answer:

Its A.  B, C, A, D

Explanation:

Answer:

100% of the energy entering earth's atmosphere comes from the sun. ~50% of the incoming energy is absorbed by the earth's surface i.e. the land and oceans.

Answer:

The tendency of a dog to bark defines entirely on the type of environment and the situation the dog looks at. Hence the correct answer is option.

When a pencil is partially submerged in a glass of water, it appears broken or offset due to the refraction of light. Refraction occurs when light passes through a medium with a different density than the one it was previously in, such as air and water. This causes the light to bend and change direction, resulting in the pencil appearing differently than it actually is.

The light that enters the water from the submerged portion of the pencil is refracted towards the normal (the imaginary line perpendicular to the surface of the water), while the light that enters the air from the exposed portion of the pencil is refracted away from the normal. This causes the image of the pencil to appear broken or offset at the water-air interface.

The degree of the bend depends on the angle of incidence and the refractive index of the medium. Hence, the amount of refraction varies with the thickness of the water column, making the pencil look even more broken or offset when viewed from different angles.

In conclusion, the illusion of a broken or offset pencil in water is caused by the refraction of light at the interface between water and air.

To Know more about refractive index visit:

brainly.com/question/30761100

#SPJ11

Answer:

Vinegar

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

Answer:.

Explanation:

Z

Boiling!

Explanation:

this is when it evaporates

Answer:

around 98 meters per second.

Explanation:

Instantaneous velocity can be found with a equation.

Vf=Vi+At

Since it fell and had no initial velocity the equation becomes

Vf=At

The Acceleration is 9.8 m/s^2

So the velocity of it fell for ten seconds is

Vf=9.8m/s^2 * 10

Vf= 98 m/s

The tension developed in the cable when s = 15m is 87.6 N (to three significant figures).

To determine the tension developed in the cable when s = 15m, we need to use the equation for the force of friction:
f_friction = μ * f_norm
where μ is the coefficient of kinetic friction, and f_norm is the normal force acting on the crate. The normal force can be calculated as:
f_norm = m * g
where m is the mass of the crate and g is the acceleration due to gravity (9.81 m/s^2).
So, f_norm = 20 kg * 9.81 m/s^2 = 196.2 N
The force of friction can be calculated as:
f_friction = μ * f_norm = 0.3 * 196.2 N = 58.86 N
Now, we can use Newton's second law of motion, which states that the net force acting on an object is equal to the product of its mass and acceleration:
F_net = m * a
where F_net is the net force, m is the mass of the crate, and a is the acceleration of the crate.
The net force in this case is the tension in the cable minus the force of friction:
F_net = T - f_friction
The acceleration of the crate can be calculated as the derivative of the velocity with respect to time:
a = dV/dt = d/dt(V(0.06s^(3/2))) = (0.09s^(1/2)) m/s^2
Now we can plug in the values and solve for the tension:
T - f_friction = m * a
T - 58.86 N = 20 kg * (0.09s^(1/2)) m/s^2
T = 58.86 N + 1.8s^(1/2) N
When s = 15m, the tension in the cable is:
T = 58.86 N + 1.8(15)^(1/2) N = 87.58 N

For more such questions on tension

brainly.com/question/13955375

#SPJ11

The heat engine operating on a Carnot cycle absorbs 450 J of heat per cycle and does 117 J of work per cycle.

The work done by a heat engine can be determined using the formula:

Work = Efficiency x Heat Absorbed

In this case, the efficiency is given as 26.0% or 0.26. The heat absorbed per cycle is given as 450 J.

To find the work done per cycle, we can substitute these values into the formula:

Work = 0.26 x 450 J

Work = 117 J

Therefore, the heat engine does 117 J of work per cycle.

In conclusion, the heat engine operating on a Carnot cycle absorbs 450 J of heat per cycle and does 117 J of work per cycle.

To know more about heat engine visit:

https://brainly.com/question/13155544

#SPJ11

Answer:

Since it us the resistance that causes the power output, it might be intuitive to think that more resistance produces more power but as P=I^2 * R one actually needs high current and low resistqnce. That means 75 W has lower resistance and higher current.

Now you may think that making the resistance very low, one gets the most power. Not so, as the circuit has wires, power source etc. All the have their resistance. In theory one gets the maximum power over a resistor when the resistor is half of the total resistance of the circuit. This in practice would be inefficient as one would lose half of the total power elsewhere. In practice circuits have fuses that limit the current and one gets the maximum power at the current the fuse is rated to. So if there is 20 A fuse, the maximum power is 2400 W and the corresponding resistance 6 ohm.

Las respuestas a cada inciso son:

a) La resistencia equivalente de la "escalera" de resistores iguales de 125 Ω que se muestra en la figura adjunta es:

\(R_{t} = 341.7 \: \Omega\)

b) La corriente a través de cada uno de los tres resistores de la izquierda si se conecta una batería de 50.0 V entre los puntos A y B es:

a) En la imagen adjuntada correspondiente a la Figura 26-40, podemos observar que las resistencias 1, 2 y 3 están en serie, por lo tanto la ressitencia equivalente entre estas 3 es:

\( R' = R_{1} + R_{2} + R_{3} \)

De aquí en adelante tendremos presente que las todas las resistencias son iguales entre sí y por ende igual a 125 Ω. Las notaciones del 1 al 9 son para poder mostrar la resolución del problema.  

Entonces:

\( R' = 3R \)

Ahora, esta resistencia está en paralelo con la resistencia R₄, por lo tanto la resistencia equivalente entre estas dos es:

\( \frac{1}{R''} = \frac{1}{R'} + \frac{1}{R_{4}} = \frac{1}{3R} + \frac{1}{R} = \frac{4R}{3R^{2}} \)

\( R'' = \frac{3}{4}R \)

Luego, esta resistencia está en serie con las resistencias R₅ y R₆, por lo tanto:

\( R''' = R'' + R_{5} + R_{6} = \frac{3}{4}R + 2R = \frac{11}{4}R \)

Esta resistencia está ahora en paralelo con R₇, entonces:

\( \frac{1}{R''''} = \frac{1}{R'''} + \frac{1}{R_{7}} = \frac{4}{11R} + \frac{1}{R} = \frac{15R}{11R^{2}} \)

\( R'''' = \frac{11}{15}R \)

Finalmente, esta resistencis está en serie con las resistencias R₈ y R₉, por lo tanto la resistencia total es:

\(R_{t} = R'''' + R_{8} + R_{9} = \frac{11}{15}R + 2R = \frac{41}{15}R = \frac{41}{15}*125 \: \Omega = 341.7 \: \Omega\)

b) Para este inciso debemos usar la Ley de Kirchhoff, pues tenemos tres mallas. Supondremos que las corriente de cada malla fluiran en sentido horario, por lo tanto las ecuaciones de para cada malla serán:

Malla 1

Segun la ley de Ohm tenemos:

\(V-i_{1}R-i_{3}R=0\) (1)

Malla 2

\(-i_{2}R-i_{5}R-i_{2}R+i_{3}R=0\) (2)

Malla 3

\(-i_{4}R-i_{4}R-i_{4}R+i_{5}R=0\) (3)

Recordemos tambien que:

\(i_{1}=i_{2}+i_{3}\) (4)

\(i_{2}=i_{4}+i_{5}\) (5)

Lo que debemos hacer ahora es resolver el sistema de ecuaciones y encontrar los valore de las corrientes. Por lo tanto, los valores de las corrientes serán:

\(i_{1}=3/13\: A\)

\(i_{2}=4/65\: A\)

\(i_{3}=11/65\: A\)

\(i_{4}=1/65\: A\)

\(i_{5}=3/65\: A\)

Finalmente:

Pudes aprender mas de mallas aquí:

https://brainly.lat/tarea/11593276

Answer:

E) 147 V

Explanation:

Ra+Rb+Rc = 14.0

V = IR

V = (10.5)(14.0)

V = 147 V

The potential difference across the source will be c)12V

Ohm's law states that  the current through a conductor between two points is directly proportional to the voltage across the two points .

since , R(A) , R(B) AND R(C) are in parallel combination , hence  equivalent

resistance of the circuit will be

1/R = 1/R(A) + 1/ R(B) + 1/ R(C)

1/R= 1/2 + 1/4 +1/8

1/R = 7/8

R = 8/7 ohm

from ohm's law

Voltage = current * resistance

V( source ) = current (in circuit ) * R (equivalent resistance)

V = 10.5 * (8/7)

V = 12 V

The potential difference across the source will be c) 12V

learn more about ohm's law :

https://brainly.com/question/14874072?referrer=searchResults

#SPJ3

Answer:

76.9231

Explanation:

Divide 400m by 5.2 to get the answer.

Speed = (distance) / (time to cover the distance)

Speed = (400 m) / (5.2 minutes)

Speed = (400 m) / (312 seconds)

Speed = 1.28 m/s

There's not enough given information to find his velocity.

(I'll be honest with ya, Flash: 1.28 m/s is no big deal. It's only about 2.87 miles per hour. My dog can walk faster than that, and so can most healthy people. If that's the best you can do, then you probably shouldn't be running around chasing bad guys.)

To run a 50 W lightbulb for 2.5 years, approximately 1.384 × 10⁸ grams of matter would have to be totally destroyed.

To calculate the amount of matter that would need to be destroyed, we can use Einstein's mass-energy equivalence principle, which states that mass and energy are interchangeable and related by the equation E = mc².

Power of the lightbulb: P = 50 W

Time: t = 2.5 years = 2.5 * 365 * 24 * 60 * 60 seconds

Total energy consumed: E = P * t = 50 W * 2.5 * 365 * 24 * 60 * 60 seconds

Using the mass-energy equivalence principle, E = mc², we can solve for the mass (m):

m = E / c²

Speed of light: c ≈ 3 * 10⁸ m/s

Substituting the values:

m = (50 W * 2.5 * 365 * 24 * 60 * 60 seconds) / (3 * 10⁸ m/s)²

Calculating the result:

m ≈ 1.384 * 10⁸ grams

Approximately 1.384 × 10⁸ grams of matter would need.

learn more about mass-energy equivalence principle here:

https://brainly.com/question/32060648

#SPJ4

To run a 50-watt lightbulb for 2.5 years, approximately 0.0438 grams of matter would have to be completely annihilated. This is based on the conversion of energy and mass according to Einstein's equation E = mc^2.

Firstly, we need to convert the given time, 2.5 years, into seconds, which is the basic unit used in physics for time. So, 2.5 years equals approximately 2.5 * 365 * 24 * 60 * 60 = 7.89 * 10^7 (78900000) seconds.

Next, knowing that energy consumption of a device, such as a lightbulb, can be formulated as power times time, (E = Pt), the total energy needed for a 50-watt lightbulb to operate for 2.5 years would be: E = 50 Watts * 7.89 * 10^7 seconds = 3.94 * 10^9 (3940000000) Joules.

Now, using Einstein’s equation E = mc^2 (Energy equals mass times the speed of light squared), we can solve for the mass (m) with m= E/c^2. Given that the speed of light (c) is approximately 3 × 10^8 meters per second, the mass (m) destroyed to generate this amount of energy is roughly m = 3.94 * 10^9 Joules / (3*10^8)^2 = 4.38 * 10^-5 kg, or 0.0438 grams.

So, about 0.0438 grams of matter would need to be totally destroyed to run a 50-watt lightbulb for 2.5 years.

https://brainly.com/question/33439849

#SPJ12

Given :

A rectangular solid box of aluminum is heated.

To Find :

Which of the following is not true.

A) Its mass remains constant

C) its density increase

B) Its volume increase

D) none of the above​

Solution :

We know, when an object is heated it expands.

Objects expands means that the volume increases but mass remains same by conservation of mass.

Since mass remains constant and volume increases.

So, density will decrease.

Hence, this is the required solution.