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4 years ago

A box with a total surface area of 1.88 m^2

Physics

1 answer:

Veseljchak [2.6K]4 years ago

3 0

Answer:9.8x10^(-3) w/m°C

Explanation:

Quantity of heat(Q)=14.1w

Distance(d)=2.44cm=2.44/100=0.0244m

Area(a)=1.88m^2

Temperature change(t)=18.6°C

thermal conductivity(k)=?

K=(Qxd) ➗ (a x t)

K=(14.1x0.0244) ➗ (1.88x18.6)

K=0.34404 ➗ 34.968

K=9.8x10^(-3) w/m°C

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A ball with a mass of 0.5 kg is attached to one end of a light rod that is 0.5 m long. The other end of the rod is loosely pinne

prohojiy [21]

Answer:

The tension in the rod as the ball moves through the bottom circle is 9.8 N

Explanation:

When the ball is released from rest, the centripetal force equals the weight of the ball. So mv²/r = mg where m = mass of ball = 0.5 kg, v = speed of ball, r = radius of vertical circle = length of rod = 0.5 m and g = acceleration due to gravity = 9.8 m/s²

v = √gr = √9.8 m/s² × 0.5 m = √4.9 = 2.21 m/s

Now at the bottom of the circle T - mg = mv²/r where T = tension in the rod

T = m(g + v²/r)

= m(g + (√gr)²/r)

= m(g+ gr/r)

= m(g + g)

= 2mg

= 2 × 0.5 kg × 9.8 m/s²

= 9.8 N

So, the tension in the rod as the ball moves through the bottom circle is 9.8 N

8 0

4 years ago

A pressure vessel that has a volume of 10m3 is used to store high-pressure air for operating a supersonic wind tunnel. If the ai

Anna71 [15]

Answer:

The mass of air stored in the vessel is 235.34 kilograms.

Explanation:

Let supossed that air inside pressure vessel is an ideal gas, The density of the air ( $\rho$ ), measured in kilograms per cubic meter, is defined by following equation:

$\rho = \frac{P\cdot M}{R_{u}\cdot T}$ (1)

Where:

$P$ - Pressure, measured in kilopascals.

$M$ - Molar mass, measured in kilomoles per kilogram.

$R_{u}$ - Ideal gas constant, measured in kilopascal-cubic meters per kilomole-Kelvin.

$T$ - Temperature, measured in Kelvin.

If we know that $P = 2026.5\,kPa$ , $M = 28.965\,\frac{kg}{kmol}$ , $R_{u} = 8.314\,\frac{kPa\cdot m^{2}}{kmol\cdot K}$ and $T = 300\,K$ , then the density of air is:

$\rho = \frac{(2026.5\,kPa)\cdot \left(28.965\,\frac{kg}{kmol} \right)}{\left(8.314\,\frac{kPa\cdot m^{2}}{kmol\cdot K} \right)\cdot (300\,K)}$

$\rho = 23.534\,\frac{kg}{m^{3}}$

The mass of air stored in the vessel is derived from definition of density. That is:

$m = \rho \cdot V$ (2)

Where $m$ is the mass, measured in kilograms.

If we know that $\rho = 23.534\,\frac{kg}{m^{3}}$ and $V = 10\,m^{3}$ , then the mass of air stored in the vessel is:

$m = \left(23.534\,\frac{kg}{m^{3}} \right)\cdot (10\,m^{3})$

$m = 235.34\,kg$

The mass of air stored in the vessel is 235.34 kilograms.

7 0

3 years ago

Which explanation of the solar system best fits the observations of the planets and how they orbit the sun?Question options:The

diamong [38]

<h2>Answer: The planets formed at the center of a collapsing spinning cloud of gas and dust.</h2>

The most accepted theory so far, in relation to the formation of our solar system is that it was originated by the contraction of a cloud of interstellar gas due to its own gravity.

To understand it better:

According to this theory, a cloud of gas and interstellar dust began to shrink due to its own gravity. This led to the increase in the temperature of the system, which began to rotate forming a large gas sphere in the center (the Sun) with a flat disk around it.

This is how the Sun formed from the sphere in the center and the planets formed from the disk orbiting in the same plane.

6 0

4 years ago

A group of equal resistors connected in series, so their equivalent resistance was 100 1 and when they connected in parallel the

kicyunya [14]

Answer:

i recommend "the organic chemistry tutor" on yt

3 0

3 years ago

A book light has a 1.4 W, 4.8 V bulb that is powered by a transformer connected to a 120 V electric outlet. The secondary coil o

VLD [36.1K]

Answer:

Turns of the primary coil: 500

Current in the primary coil: Ip= 0.01168A

Explanation:

Considering an ideal transformer I can propose the following equations:

Vp×Ip=Vs×Is

Vp= primary voltaje

Ip= primary current

Vs= secondary voltaje

Is= secondary current

Np×Vs=Ns×Vp

Np= turns of primary coil

Ns= turns of secondary coil

From these equations I can clear the number of turns of the primary coil:

Np= (Ns×Vp)/Vp = (20×120V)/4.8V = 500 turns

To determine the current in the secondary coil I use the following equation:

Is= (1.4W)/4.8V = 0.292A

Therefore I can determine the current in the primary coil with the following equation:

Ip= (Vs×Is)/Vp = (4.8V×0.292A)/120V = 0.01168A

5 0

3 years ago