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3 years ago

Which statement is true?

Physics

1 answer:

marshall27 [118]3 years ago

3 0

Answer:

B.The galaxies are moving away from us.

Explanation:

Universe is expanding from the time of Big bank.

AS the universe expand Galaxies get away from each other.Latest studies stay that the acceleration of universe is uncreasing due to Dark Energy.

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Does water transmit light

liq [111]

While the answer is that it does, it transmits light VERY poorly. Most of the light bounces off it and the rest is refracted into the ocean. This is why you can't see much that is far away from you in the ocean unlike if you're just on land.

3 0

3 years ago

The big bang theory of the information and expansion of the universe is supported by the observed

dusya [7]

By Hubble theory in which universe is expanding,

6 0

3 years ago

Block 1 (mass 2.00 kg) is moving rightward at 10.0 m/s and block 2 (mass 5.00 kg) is moving rightward at 3.00 m/s. The surface i

DaniilM [7]

Answer:

a) 0.25m

b) 5 m/s

Explanation:

When the spring is compressed both boxes are moving with the same velocity, so applying the principle of linear momentum conservation:

$m1*v_{o1}+m2*v_{o2}=(m1+m2)*v\\v=5m/s$

Now applying the principle of energy conservation:

$K1+K2+U_{g1}-U_e=Kf+U_{g2}\\K1+0-U_e=K2+0\\U_e=K1+K2-kf\\\frac{1}{2}*k*x^2+=\frac{1}{2}*m1*v1^2+\frac{1}{2}*m1*v1^2-\frac{1}{2}*(m1+m2)*v^2\\\\x=\sqrt{\frac{2.00kg*(10m/s)^2+5.00kg*(3.00m/s)^2-7.00kg*(5m/s)^2}{1120N/m}}\\x=0.25m$

We got that the maximum compression is 0.25m.

5 0

3 years ago

Help please I give brainliest

shutvik [7]

Answer:

can someone help me with physics to

7 0

3 years ago

Read 2 more answers

The emissivity of galvanized steel sheet, a common roofing material, is 0.13 at temperatures around 300 K, while its absorptivit

vfiekz [6]

Answer:

Total heat transfer rate is combined convection and radiation transfer rate, multiplied with absorptivity factor. From that equation you can find temperature of the roof using iteration method.

Explanation:

<u>Known:</u>

steel sheet roof emissivity ∈ = 0.13

steel sheet roof absorptivity $\alpha$ _s = 0.65

air temperature T∞ = 16°C ...= 289K

heat transfer rate $G_s$ = 750 W/m2

natural convection h = 7W/m2K

Total heat transfer rate is combined heat transfer rate of convection and radiation, multiplied with absorptivity factor:

$\alpha$ $G_s$ = $q_{conv} +q_{rad} =hA($ T∞- $T_m$ )+∈σA( $T_{surf} -T_{s} )$

$\alpha$ $G_s$ - $h(T_s-$ T∞)-∈σ( $T_{s} -T_{surf} )$ =0

2562-7 $T_s$ -7.371*10^-9=0

Use iteration method to solve for $T_s$

$T_s$ =350.17 K...=77.17°C

In this particular situation, cat would not be comfortable with walking on a roof since its surface temperature is 77.17°C which may even cause burns to its paws.

4 0

3 years ago