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makkiz [27]
3 years ago
8

An observation of the red shift of galaxies suggestst that the universe is

Physics
1 answer:
Rufina [12.5K]3 years ago
3 0
A) Expanding. We know this because it has a similar effect with sound. When a car goes by the pitch gets deeper and deeper. It's because you're receiving less waves. Same thing for light but instead of a pitch it's light, and the farther spread the waves - the redder, the closer and more contracted - the bluer
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A string is stretched and fixed at both ends, 200 cm apart. If the density of the string is 0.015 g/cm, and its tension is 600 N
Gre4nikov [31]

Answer:

<h2>f₀ = 158.12 Hertz</h2>

Explanation:

The fundamental frequency of the string  f₀ is expressed as f₀ = V/4L where V is the speed experienced by the string.

V = \sqrt{\frac{T}{\mu} } where T is the tension in the string and  \mu is the density of the string

Given T = 600N and \mu = 0.015 g/cm  = 0.0015kg/m

V = \sqrt{\frac{600}{0.0015} }\\ \\V =  \sqrt{400,000}\\ \\V = 632.46m/s

The next is to get the length L of the string. Since the string is stretched and fixed at both ends, 200 cm apart, then the length of the string in metres is 2m.

L = 2m

Substituting the derived values into the formula f₀ = V/2L

f₀ = 632.46/2(2)

f₀ = 632.46/4

f₀ = 158.12 Hertz

Hence the fundamental frequency of the string is 158.12 Hertz

5 0
4 years ago
A chair of weight 125 N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 3
iris [78.8K]

Answer:

N = 148.10N

Explanation:

GIVEN

Weight =125 N

force = 35

angle =42°

since there is no vertical acceleration a_{y} = 0 from

free body diagram

\Sigma fa_{y} = ma_{y} = 0

N-W-Fsin42\degree = 0\\\\N= W+Fsin42\\N = 125+35\times 0.66\\N = 148.10 N

5 0
4 years ago
Nuclear reactors use fuel rods to heat water and generate steam. Is this process endothermic or exothermic?
Anna71 [15]

Explanation:

Exothermic reaction is defined as the reaction in which release of heat takes place. This also means that in an exothermic reaction, bond energies of reactants is less than the bond energies of products.

Hence, difference between the energies between the reactants and products releases as heat and therefore, enthalpy of the system will decrease.

Whereas in an endothermic reaction, heat is supplied from outside and absorbed by the reactant molecules. Hence, enthalpy of the system increases.

As water acts as a coolent and when fuel rods in a nuclear reactor are immersed in it then heat created by coolent is absorbed by water and then it changes into steam.

Since, absorption of heat occurs in the nuclear reactor. Therefore, it is an endothermic reaction.

Thus, we can conclude that nuclear reactors use fuel rods to heat water and generate steam. This process is endothermic.

5 0
3 years ago
Read 2 more answers
Which of the following is NOT a correct statement?*
lozanna [386]

AnswerAmontons's law. If the temperature is increased, the average speed and kinetic energy of the gas molecules increase. ... If the gas volume is decreased, the container wall area decreases and the molecule-wall collision frequency increases, both of which increase the pressure exerted by the gas (Figure 1).:

Explanation:

5 0
3 years ago
Are light waves longitudinal or transverse
Marysya12 [62]

Answer:

Transverse

Explanation:

There are two types of waves, according to the direction of their oscillation:

- Transverse waves: in a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. Examples of transverse waves are electromagnetic waves

- Longitudinal waves: in a longitudinal wave, the direction of the oscillation is parallel to the direction of motion of the wave. Examples of longitudinal waves are sound waves.

Light waves corresponds to the visible part of the electromagnetic spectrum, which includes all the different types of electromagnetic waves (which consist of oscillations of electric and magnetic fields that are perpendicular to the direction of propagation of the wave): therefore, they are transverse waves.

6 0
3 years ago
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