The density of air is 1.3 kg/m'. Calculate the mass of air in the room.

Answer:

D

Explanation:

Cá xương, chim, thú, cá sấu không có sự pha trộn máu giàu O2 và máu giàu CO2 ở tim vì tim cá có 2 ngăn, tim các loài chim, thú, cá sấu có 4 ngăn

Answer:

not sure just need points

Explanation:

a+b+c

Answer:

The laws of liquid pressure are: ... The liquid pressure at a point inside the liquid is same in all directions. The liquid pressure at a point inside the liquid is directly proportional to the depth of that point from the free surface of liquid. The pressure of liquid at same depth is different for different liquids

Answer:

The laws of liquid pressure:

The pressure that is inside the liquid rises with the intensity from the surface of a liquid.

The term fluid:

Fluid is basically liquid and a substance that is known to have no certain shape. The opposite of the term fluid would be solid.

Answer:

sorry I don't understand this language

Answer:

Average speed = 0.35 m/s

Explanation:

Given the following data;

Distance = 1.3 Km

Time = 62 minutes

To find the average speed in m/s;

First of all, we would convert the quantities to their standard unit (S.I) of measurement;

Conversion:

1.3 kilometres to meters = 1.3 * 1000 = 1300 meters

For time;

1 minute = 60 seconds

62 minutes = X

Cross-multiplying, we have;

X = 62 * 60

X = 3720 seconds

Now, we can calculate the average speed in m/s using the formula;

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

[tex] Speed = \frac {1300}{3720} [/tex]

Average speed = 0.35 m/s

Answer:

2.5 m/s²

Explanation:

The given parameters are;

The mass of the car, m = 2,000 kg

The radius of the car, r = 40.0 m

The coefficient of friction between the car tires and the road, μ = 0.500

The constant speed with which the car moves, v = 10.0 m/s

The normal reaction of the road on the car, N = The weight of the car;

∴ N = m × g

Where;

g = The acceleration due to gravity ≈ 9.81 m/s²

N ≈ 2,000 kg × 9.81 m/s² = 19,620 N

The frictional force, [tex]F_f[/tex] = μ × N

The centripetal force, [tex]F_c[/tex] = m·v²/r

The car moves without slipping when [tex]F_f[/tex] = [tex]F_c[/tex]

Therefore, [tex]F_f[/tex] = 0.500 × 19,620 N = 2,000 kg × [tex]v_{max}[/tex]²/40.0 m

∴ [tex]v_{max}[/tex] = √(0.500 × 19,620 N × 40.0 m/2,000 kg) ≈ 14.007 m/s

Therefore, the velocity with which the car moves, v < [tex]v_{max}[/tex]

The cars centripetal acceleration, [tex]a_c[/tex] = v²/r

∴ [tex]a_c[/tex] = (10.0 m/s)²/40.0 m = 2.5 m/s²

The cars centripetal acceleration as it goes round the turn, [tex]a_c[/tex] = 2.5 m/s².

La respuesta correcta para esta pregunta abierta es la siguiente.

Te compartimos las tres ideas que te pueden ayudar para hacer tu artículo.

Título:

La Educación Física, una prioridad para las escuelas.

Existe una frase milenaria que se le atribuye a los griegos que dice "Mente sana en cuerpo sano."

Y es muy cierta.

Las escuelas deberían considerar seriamente aumentar el número de horas semanales para la impartición de la educación física por las siguientes razones.

1.- La educación física es vital para el desarrollo físico del estudiante. Desde los grados más básicos, las escuelas deberían fortalecer la enseñanza de la educación física por motivos de salud, y dejar este buen hábito en los alumnos para toda la vida.

2.- La educación física, mejora el rendimiento académico ya que ayuda oxigenando los músculos, fortaleciendo el cerebro para que pueda concentrase mejor, despeja a los alumnos de tal forma que puedan regresar a los salones e clase más "despiertos."

3.- La educación física sirve para introducir la importancia de practicar deporte toda la vida, y hacerlo en la etapa escolar a través de equipos deportivos como el Futbol Americano, el beisbol, el basquetbol, el volibol, el soccer, y otros tantos.

Este idea del trabajo en equipo a través del deporte es muy importante para desarrollar habilidades como el liderazgo, el compromiso, la constancia y el superar la adversidad.

El profesor de educación física debe enseñarte la forma correcta de respirar cuando haces ejercicio, la importancia de la relajación del cuerpo para iniciar una actividad. El profesor debe hacer énfasis en la etapa del calentamiento y el estiramiento para preparar al cuerpo antes de realizar el ejercicio. Así como muchas otras enseñanzas.

Por esa razón, las escuelas deberían considerar seriamente la posibilidad de aumentar las horas de educación física por semana.

Answer:

Explanation:

The only one that doesn't have a time unit that is squared is the one that is a label for speed or velocity. Acceleration has a label with the time unit squared, like m/s/s. Choice D is the only unit for speed/velocity.

Answer: D

Explanation: metres per second (m/s)

Answer:

The final translational seed at the bottom of the ramp is approximately 4.84 m/s

Explanation:

The given parameters are;

The radius of the sphere, R = 2.50 cm

The mass of the sphere, m = 4.75 kg

The translational speed at the top of the inclined plane, v = 3.00 m/s

The length of the inclined plane, l = 2.75 m

The angle at which the plane is tilted, θ = 22.0°

We have;

[tex]K_i[/tex] + [tex]U_i[/tex] = [tex]K_f[/tex] + [tex]U_f[/tex]

K = (1/2)×m×v²×(1 + I/(m·r²))

I = (2/5)·m·r²

K =  (1/2)×m×v²×(1 + 2/5) = 7/10 × m×v²

U = m·g·h

h = l×sin(θ)

h = 2.75×sin(22.0°)

∴ 7/10×4.75×3.00² + 4.75×9.81×2.75×sin(22.0°) = 7/10 × 4.75×[tex]v_f[/tex]² + 0

7/10×4.75×3.00² + 4.75×9.81×2.75×sin(22.0°) ≈ 77.93

∴ 77.93 ≈ 7/10 × 4.75×[tex]v_f[/tex]²

[tex]v_f[/tex]² = 77.93/(7/10 × 4.75)

[tex]v_f[/tex] ≈ √(77.93/(7/10 × 4.75)) ≈ 4.84

The final translational seed at the bottom of the ramp, [tex]v_f[/tex] ≈ 4.84 m/s.

It is a process of offering jobs to desired candidates and offering jobs to the desired applicant.

Answer:

g = 5 m/s square

Explanation:

Weight(W), Mass(m), Gravity(g)

W = mg

1,000N = 200g

g = 1000/200

g = 5 m/s square

The three dimensional space of a body is called volume

Answer:

Because matter has been squeezed into a tiny space.

Explanation:

According to NASA, this can happen when a star is dying.

A black hole has no more gravity than the same amount of matter in any other form.

But remember that the gravitational forces are stronger as you get closer to the center of the body. The mass of a black hole is packed into such a small size (theoretically zero !) that you can get very close to its center. THAT'S where its gravity is hugely strong.

Answer:

The effect of gravity extends from each object out into space in all directions, and for an infinite distance. However, the strength of the gravitational force reduces quickly with distance. Humans are never aware of the Sun's gravity pulling them because the pull is so small at the distance between the Earth and Sun.

Answer:

The Earth's gravitational force accelerates objects when they fall. It constantly pulls, and the objects constantly speed up.

Explanation:

Explanation:

initial velocity(u)=30km/hr = 30*1000/60*60=8.33 m/s

final velocity(v) =60km/hr = 60*1000/60*60 =16.67 m/s

time taken(t) = 1 minutes

= 60 seconds

Now,

Average velocity = u+v/2

= 8.33 m/s + 16.67m/s÷2

=12.5 m/s

Answer:

6,76 x 10^-7 T.

Explanation:

The Magnetic field formula for a wire is B=(μ x I)/2πd , where μ (=4π x 10^-7 Tm/A) is the permeability, I is the current and d is the distance.

Answer: The answer is B

Explanation:

There are 4 fundamental forces that hold matter together.

- Gravitational Force

- Electromagnetic Force

- Strong Nuclear Force

- Weak Nuclear Force

We have barely just scratched the info about nuclear forces but the reason why B is the answer to the question is that Strong nuclear force actually holds the protons and neutrons together in the nucleus of an atom, much like the picture in B.

Answer: B

Explanation:

Answer:

a. there is a pH gradient that parallels the electric field gradient.

Explanation:

Gel electrophoresis is a technique used to separate DNA fragments according to their size. DNA samples are loaded in the wells and then electric current is applied to pull the DNA fragments out from the gel. Isoelectric gel electrophoresis is a process in which negatively charged DNA fragments are separated from the gel.

Answer:

1) Force is the action of pull or push that changes or tends to change the position of a body. Its SI unit is newton.

2) The types of force are:

• Pulling and Pushing force

• Frictional force

• Gravitational force

•Muscular force

• Centripetal and Centrifugal force

[tex] \\ \tt \longmapsto \: h = - 4.8 {t}^{2} + 8.2t + 1.8 \\ \\ \tt \longmapsto \: h = - 4.8(1.7) {}^{2} + 8.2 \times 1.7 + 1.8 \\ \\ \tt \longmapsto \: - 4.8 \times 2.89 + 1.39 + 1.8 \\ \\ \tt \longmapsto \: 13.8 + 1.39 + 1.8 \\ \\ \tt \longmapsto \: 17.06[/tex]

Answer:

C. 540 N

Explanation:

Let suppose that system formed by the athlete and the load are in equilibrium. By Newton's Laws of Motion, we use the moment equation with respect to the feet of the athlete to determine the upward force exerted by his two arms:

[tex]\Sigma M = -F\cdot r_{1} + m_{L}\cdot g \cdot r_{2} + m_{A}\cdot g \cdot r_{3} = 0[/tex]

[tex]F = \frac{(m_{L}\cdot r_{2} + m_{A}\cdot r_{3})\cdot g}{r_{1}}[/tex] (1)

Where:

[tex]m_{L}[/tex] - Mass of the load, in kilograms.

[tex]m_{A}[/tex] - Mass of the athlete, in kilograms.

[tex]g[/tex] - Gravitational acceleration, in meters per square second.

[tex]r_{1}[/tex], [tex]r_{2}[/tex], [tex]r_{3}[/tex] - Distances with respect to the feet, in meters.

[tex]F[/tex] - Upward force exerted by his two arms, in newtons.

If [tex]m_{L} = 6\,kg[/tex], [tex]r_{2} = 1.20\,m[/tex], [tex]m_{A} = 70\,kg[/tex], [tex]r_{3} = 0.90\,m[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]r_{1} = 1.30\,m[/tex], then the upward force is:

[tex]F = \frac{[(6\,kg)\cdot (1.20\,m)+(70\,kg)\cdot (0.90\,m)]\cdot \left(9.807\,\frac{m}{s^{2}} \right)}{1.30\,m}[/tex]

[tex]F = 529.578\,N[/tex]

The upward force exerted by his two arms is 529.578 newtons. (Right answer: C)

One way to measure the volume of any irregular object (in your case, a stone) is to submerge it completely under water and measure the change in the height of the water level. This change in the water level (let's say it goes from 50 mL to 65 mL) indicates that the stone has a volume of 15 mL .

The dimension of a/b where x is the distance and t is the time is T

Given the expression

x = at + bt²

where

x is the distance

t is the time

Based on the homogeneity principle, the expression on the left-hand side must be equal to that on the right. Hence;

x = at

[tex]a = \frac{x}{t}[/tex]

Since x is the distance and distance is measured in metres, the dimension equivalent will be the length 'L'

Since t is the time and time is measured in seconds, the dimension equivalent will be the seconds 'T'

[tex]a=\frac{L}{T}[/tex]

Similarly;

x  = bt²

[tex]b=\frac{x}{t^2}\\b=\frac{L}{T^2}[/tex]

Next is to get a/b;

[tex]\frac{a}{b} = \frac{L}{T} \div \frac{L}{T^2}\\\frac{a}{b} = \frac{L}{T}*\frac{T^2}{L} \\\frac{a}{b} =\frac{T^2}{T}\\\frac{a}{b} =T[/tex]

Hence the dimension of a/b is T

Explanation:

a) copper

b) olive oil

Hope it helps✌✌

Answer:

B. Km/s/hr

Explanation:

have a higher intensity in the red part of the spectrum

Because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum

Most galaxies' spectra have been redshifted, which means that their spectral lines are now pushed away from their normal or rest wavelengths and towards longer wavelengths. When an object travels away from an observer, the Doppler effect causes the shift phenomenon.

The Big Bang hypothesis and the concept of the expanding universe, show that galaxies are moving away from us, observed from the redshift lines.

The waves' apparent wavelengths shift as a result, changing the color of light waves or the pitch of sound waves.

Hence, because of the Doppler effect, the spectra of most galaxies show redshifts. This means that their spectral lines Group of answer choices always are in the red part of the visible spectrum.

To learn more about the Doppler effect, here:
https://brainly.com/question/28106478

#SPJ6

Answer:

is it from positive to negative am I right tell me if I am wrong

Answer:

positive to negative

The flow of electric current is similar to the flow of water which is from higher level to lower level.

The electric current flow from higher potential region(positive* low concentration of electron) to lower potential region(negative*high concentration of electron)