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4 years ago

How do stars serve as evidence for the expansion of the universe and the Big Bang theory?

Physics

1 answer:

castortr0y [4]4 years ago

7 0

Answer:

The Doppler red-shift of light observed from distant stars and galaxies gives evidence that the universe is expanding (moving away from a central point). This allows for Big Bang Theory, because after a “bang” occurs all of the matter moves away from the point of origin.

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When a gas is rapidly compressed (say, by pushing down a piston) its temperature increases. When a gas expands against a piston,

shusha [124]

Answer:

Explained in explanation

Explanation:

The first law of thermodynamics states that the change in internal energy of a system(ΔU) is equal to the sum of the net heat transfer into the system(Q) and the net work done on the system(W). In equation, this law is;

ΔU = Q + W

Now, when there's gas inside a container with a movable piston that's tightly fitting, we will assume that the piston can move up and down thereby compressing the gas or allowing the gas to expand against it.

Now these gas molecules inside the container possess kinetic energy. Thus, the internal energy(U) of the system is simply the sum of all the kinetic energies of the individual gas molecules present in the container.

Therefore, if the temperature(T) of the gas increases, then the speed and internal energy(U) of the gas molecules will also increase. In the same way, if the temperature of the gas decreases, the speed and internal energy of the gas molecules would also decrease.

Now, back to the question, when the piston is pushed down, it does work on the gas and the gas does negative work on the piston. Thus, the gas will be get compressed to a smaller space, and thereby making the gas molecules to hit the piston at a faster rate. Thus, there is a decrease in speed and as we saw earlier that when there is a decrease in speed, it means temperature has decreased.

Whereas, when the piston is moved up, the gas does positive work on the piston and the speed of the gas molecules will increase. Like I said earlier that increase in speed means increase in temperature.

4 0

3 years ago

The membrane that surrounds a certain type of living cell has a surface area of 7.1 x 10-9 m2 and a thickness of 1.5 x 10-8 m. A

hoa [83]

Answer:

Q = +1.4 pC

Explanation:

The capacitance of any capacitor, by definition, is as follows:
$C = \frac{Q}{V} (1)$
Applying Gauss'Law and the definition of electric potential, it can be showed that the capacitance of a parallel-plate capacitor can be expressed as follows:
$C = \frac{\epsilon_{r}*\epsilon_{0} * A}{d} (2)$
Where εr is the dielectric constant of the material that fills the space between the plates, A is the area of one of the plates, and d, is the separation between them.
Replacing by the givens in (2) we can find the value of the capacitance C, as follows:

$C = \frac{\ 4.4*8.85e-12C2/N*m2*7.1e-9m2}{1.5e-8m} = 18.4e-12 F = 18.4 pF$

Replacing the values of C and V in (1), we can solve for Q, as follows:

$Q = C*V = 18.4e-12 F* 75.9e-3 V = 1.4e-12 C = +1.4 pC$

As the outer surface is at a higher potential that the inside surface, the charge on it must be positive, and is equal to +1.4 pC.

7 0

3 years ago

The starter motor of a car engine draws a current of 140A from the battery. The copper wire to the motor runs for 0.90s until th

nasty-shy [4]

"1 Ampere" (A) means "1 coulomb of charge per second"

140 A means 140 coulombs per second

(140 coulomb/sec) x (0.9 sec) = 126 coulombs of charge.

Go a little farther:

Electrons are the things that move through wire carrying charge.

6.25 x 10¹⁸ electrons carry 1 coulomb of charge.

126 coulombs = 787,500,000,000,000,000,000 electrons (rounded)

8 0

3 years ago

The speed of light is 300,000,000 m/s, what is the frequency of an x-ray that has a wavelength of .1 m? ____Hz?

Fittoniya [83]

Answer:

Explanation:

The speed of light is 300,000,000 m/s. Shat is the frequency of microwaves with a wavelength of 0.01 meter

8 0

2 years ago

Will mark as brainliest . pls help

ipn [44]

Answer:

answer D

Explanation:

circuit breaker is useful when you do something with your domestic electric circuit..

3 0

3 years ago

How do stars serve as evidence for the expansion of the universe and the Big Bang theory?​

How do stars serve as evidence for the expansion of the universe and the Big Bang theory?