The fundamental cause of a variable star's change in luminosity is that the star's _____ is changing.

Given the Hubble's constant, the approximate age of the universe is 5.88 × 10⁹ Years.

Given the data in the question;

Hubble's constant; [tex]H_0 = 51km/s/Mly[/tex]

Age of the universe; [tex]t = \ ?[/tex]

We know that, the reciprocal of the Hubble's constant ( [tex]H_0[/tex] ) gives an estimate of the age of the universe ( [tex]t[/tex] ). It is expressed as:

[tex]Age\ of\ Universe; t = \frac{1}{H_0}[/tex]

Now,

Hubble's constant; [tex]H_0 = 51km/s/Mly[/tex]

We know that;

[tex]1\ light\ years = 9.46*10^{15}m[/tex]

so

[tex]1\ Million\ light\ years = [9.46 * 10^{15}m] * 10^6 = 9.46 * 10^{21}m[/tex]

Therefore;

[tex]H_0 = 51\frac{km}{\frac{s}{Mly} } = 51000\frac{m}{s\ *\ Mly} \\\\H_0 = 51000\frac{m}{s\ *\ (9.46*10^{21}m)} \\\\H_0 = 5.39 *10^{-18}s^{-1}\\[/tex]

Now, we input this Hubble's constant value into our equation;

[tex]Age\ of\ Universe; t = \frac{1}{H_0}\\\\t = \frac{1}{ 5.39 *10^{-18}s^{-1}} \\\\t = 1.855 * 10^{17}s\\\\We\ convert\ to\ years\\\\t = \frac{ 1.855 * 10^{17}}{60*60*24*365}yrs \\\\t = \frac{ 1.855 * 10^{17}}{31536000}yrs\\\\t = 5.88 *10^9 years[/tex]

Therefore, given the Hubble's constant, the approximate age of the universe is 5.88 × 10⁹ Years.

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Hi there!

We know that:

Initial Total Mechanical Energy = Final Total Mechanical Energy

(Ei = Ef)

In this instance:

Ei = Gravitational Potential Energy

Ef = Kinetic Energy

In the absence of friction, ALL of the initial potential energy will be changed into kinetic energy at the bottom of the slide. Thus, the maximum kinetic energy of the child will be 1800 J.

Answer:

Explanation:

(i) μs = F/N = mgsinθ/mgcosθ = tanθ

  tanθ = 0.3

  θ = 16.7°

(ii) a = F/m

    a = (mgsinθ - (μk)mgcosθ) / m

    a = g(sinθ - (μk)cosθ)

    a = 9.8(sin16.7 - (0.2)cos16.7)

    a = 0.94 m/s²

(iii) s = ½at²

     t = √(2s/a)

     t = √(2(1)/0.94)

     t = 1.5 s

Answer:

Water Vapour, Carbon dioxide, methane,nitrous oxide,ozone.

Explanation:

static electricity draws energy

Answer:

(i) 0.6s (ii) 8.42m

Explanation:

U² = 6.02² + 7²

U = 9.23

angle of projection

tanø = 6.02/7

ø = 40.7

Time of fligt

t = Usinø/g

t = 9.23 sin 40.7/10

t = 0.6

H range = U²sin2ø/g

H = 9.23²sin 81.4/10

H = 8.42m

The time taken reach the maximum height is 0.6s and the horizontal range is 8.42m.

Velocity ​​is defined as the directional motion of an object which is indicated by the rate of change of position as observed from a particular frame of reference. It is measured by a particular standard of time. It is a vector quantity as it has both magnitude and direction.

It can be expressed as:

v= d/t

Where. v is the velocity in m/s

d is the displacement measured in meter 'm'

t is the time measured in seconds 's'

For above given information,

v = 6.02 +7.0j, so the initial velocity will be u

u² = 6.02² + 7²

u = 9.23m/s

Angle of projection, tanø = 6.02/7

ø = 40.7

Time taken=  t = u sinø/g

t = 9.23 sin 40.7/10

t = 0.6s

Horizontal range  = u²sin2ø/g

H = 9.23²sin 81.4/10

H = 8.42m

Thus, the time taken reach the maximum height is 0.6s and the horizontal range is 8.42m.

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Answer:

If the mass of geranium is 75 and the atomic number is 32 then it must have

N = 75 -32 = 43 neutrons

The conservation of energy allows to find the result for the point where the kinetic and potential energy are equal is;

       x = 0.026 m

Given parameters

To find

The law of the conservation of mechanical energy is one of the most important in physics, stable that if there is no friction, the mechanical energy of the system is conserved. The mechanical energy is formed by the sum of the kinetic energy and the potential energies.

               Em = K + U

Let's write the energy in two points.

Starting point. With maximum compression.

        Em₀ = U = ½ k x²

Final point. Where the kinetic and potential energy are equal.

        [tex]Em_f = K +U[/tex]  

Since the mechanical energy is constant at this point K = U, therefore we can write the energy.

        [tex]Em_f = 2U = 2 ( \frac{1}{2} \ k \ x_f^2 )[/tex]

Energy is conserved.

        [tex]Em_o = Em_f \\\frac{1}{2} \ k x_o^2 = 2 ( \frac{1}{2} \ k x_f^2)[/tex]Emo = Emf

        ½ k x² = 2 (½ k xf²)

        [tex]x_f = \frac{x_o}{2}[/tex]  

let's calculate.

        [tex]x_f = \frac{0.052}{2} \\x_f = 0.026 m[/tex]  

In conclusion using the conservation of energy we can find the point where the kinetic and potential energy are equal is;

       x = 0.026 m

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Answer:

1

Explanation:

A=mgh=0.2*10*0.5=1 J

Answer:

I think it's c but don't know for sure

Answer:

Our eyes are most sensitive to the wavelengths corresponding to the yellow and green colors of the spectrum. Flashy signs and some fire engines are painted in a yellowish-green color to attract our attention.

Answer:

sorry for you

The ratio of the man's moment of inertia in the first case (arms extended) to that in the second case (arms drawn in) is 3.2.

The relationship between the rotational frequency [tex](\(\omega\))[/tex] and moment of inertia (I) is given by the equation:

[tex]\[I_1\omega_1 = I_2\omega_2\][/tex]

where [tex]\(I_1\)[/tex]and [tex]\(I_2\)[/tex] are the moments of inertia in the two cases, and [tex]\(\omega_1\) and \(\omega_2\)[/tex] are the corresponding rotational frequencies.

Let's denote the moment of inertia in the first case (arms extended) as [tex]\(I_1\)[/tex] and in the second case (arms drawn in) as [tex]\(I_2\)[/tex]. The given rotational frequencies are [tex]\(\omega_1 = 0.25 \, \text{rev/s}\) and \(\omega_2 = 0.80 \, \text{rev/s}\)[/tex].

Using the equation [tex]\(I_1\omega_1 = I_2\omega_2\)[/tex], we can rearrange it to solve for the ratio of moments of inertia:

[tex]\[\frac{I_1}{I_2} = \frac{\omega_2}{\omega_1}\][/tex]

Substituting the given values, we have:

[tex]\[\frac{I_1}{I_2} = \frac{0.80 \, \text{rev/s}}{0.25 \, \text{rev/s}}\][/tex]

Simplifying the expression, we get:

[tex]\[\frac{I_1}{I_2} = 3.2\][/tex]

Therefore, the ratio of the man's moment of inertia in the first case (arms extended) to that in the second case (arms drawn in) is 3.2.

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Answer:

iIn a nuclear plant, the heat source is from the nuclear reaction whereas in a thermal power plant it is from the combustion of coal. The difference is in the inlet steam parameters to the turbine in a nuclear plant. Thermal power plants use steam at superheated conditions. ... The nuclear plant uses a 'wet steam turbine'.

Explanation:

The heat source in a nuclear power plant is the nuclear reaction, whereas the heat source in a thermal power plant is coal combustion. The difference is in the turbine's input steam characteristics.

Power plant is an industrial structure that generates electricity. The majority of power plants are linked to the electrical grid.

Nuclear power bare a form of thermal power plant. You have a reactor where fission takes place and heat is generated, a heat exchanger that transports this heat to where it is needed.

Thermal power plant equipment converts this heat into electric energy, usually via a steam turbine.

The reactor, heat exchanger, and thermal conversion technology all have different designs and technologies, but the overall architecture is quite similar to other types of thermal power plants.

The heat source in a nuclear power plant is the nuclear reaction, whereas the heat source in a thermal power plant is coal combustion. The difference is in the turbine's input steam characteristics.

Hence, the two types of power plants differ in  difference is in the turbine's input steam characteristics.

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Answer:

A i think its right im postivite

Answer: A. Faults

Explanation: ;-; its easy because faults are cracks and they can push layers past each other making tectonic plates rub against each other then creating a earthquake

Answer:

B.-80.35 J

i dont know the calculation

Answer:

P1 = 1.3 (500 + 60) = 728 kg-m      total momentum to right at start

P2 = (v2 - 10) 60 + 500 v2

total momentum after running at -10 with respect to cart = 728 where v2 is the new speed of the cart

728 = 560 v2 - 600

v2 = 1328 / 560 = 2.37 m/s    new speed of cart

Check:

After:    p2 for cart = 500 * 2.37 = 1186

p1 for man = (2.37 - 10) * 60 = -458

P2 = p1 + p2 = 728       total momentum unchanged

Answer:

Explanation:

Given,

As we know,

Kinetic Energy,

Therefore ,

Kinetic energy of the object is,

[tex] = \frac{1}{2} \times 12 \: kg \times 10 \: m {s}^{ - 1} \times 10 \: m {s}^{ - 1} [/tex]

= (6 × 10 × 10) J [As 'J' stands for 'joule']

= 600 J (Ans)

Answer:

a = 6.22 m//s²

Explanation:

F = ma

a = F/m

a = 573.0 / 92.1

a = 6.221498...

Answer:

[tex]\boxed {\boxed {\sf 6.22 \ m/s^2}}[/tex]

Explanation:

We are asked to find the acceleration due to gravity on another planet.

Weight is the measure of the force of gravity. Therefore, we can use the following version of the force formula:

[tex]F_g=mg[/tex]

In this formula, [tex]F_g[/tex] is the weight, m is the mass, and g is the acceleration due to gravity.

The object weights 573.0 Newtons (or 573.0 kg*m/s²) on the planet. The object has a mass of 92.1 kilograms.

Substitute these values into the formula.

[tex]573.0 \ kg*m/s^2 = 92.1 \ kg * g[/tex]

We are solving for g, so we must isolate the variable. It is being multiplied by 92.1 kilograms. The inverse of multiplication is division, so divide both sides of the equation by 92.1 kg.

[tex]\frac {573.0 \ kg*m/s^2}{92.1 \ kg}= \frac{92.1 \ kg*a}{92.1 \ kg}[/tex]

[tex]\frac {573.0 \ kg*m/s^2}{92.1 \ kg}=a[/tex]

The units of kilograms cancel.

[tex]6.22149837 \ m/s^2=a[/tex]

The original measurements of weight and mass have 4 and 3 significant figures. Our answer must have the least number of sig figs, or 3. For the number we found, that is the hundredth place. The 1 in the thousandths place tells us to leave the 2 in the hundredth place.

[tex]6.22 \ m/s^2=a[/tex]

The acceleration due ot gravity on planet Xyleneer is approximately 6.22 meters per second squared.

The increase in tension on the steel wire is 8,484.75 N.

The given parameters;

The area of the steel wire is calculated as follows;

[tex]A = \pi r^2\\\\A = \pi \times (2\times 10^{-3})^2\\\\A = 1.257 \times 10^{-5} \ m^2[/tex]

The extension of the steel wire is calculated as follows;

[tex]\Delta l = \alpha \times l\times \Delta T\\\\\Delta l = (12\times 10^{-6}) \times (8) \times (10 + 273)\\\\\Delta l = 0.027 \ m[/tex]

The increase in tension on the steel wire is calculated as follows;

[tex]E = \frac{stress}{strain } = \frac{\ F/A}{\Delta l/l} \\\\E = \frac{F\times l}{A \times \Delta l} \\\\F = \frac{E\times A \times \Delta l }{l} \\\\F = \frac{(2\times 10^{11}) \times (1.257\times 10^{-5})\times 0.027}{8} \\\\F = 8,484.75 \ N[/tex]

Thus, the increase in tension on the steel wire is 8,484.75 N.

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In Physics, energy can be defined as the ability and capacity to do work by an object or physical body.

In Physics, energy can be defined as the ability to do work. Thus, energy must be possessed or transferred to a physical object (body) before it can be used in doing a work or heating a system.

Generally, there are two (2) main types of energy and these are;

For example, you require a sufficient amount of energy to move a crate of egg across a given distance.

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Answer:. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. There are, moreover, heat and work—i.e., energy in the process of transfer from one body to another. ... All forms of energy are associated with motion.

Explanation:. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms. There are, moreover, heat and work—i.e., energy in the process of transfer from one body to another. ... All forms of energy are associated with motion.

From the information provided in the question, the mass of the beaker is 144.4 g.

From the information provided in the complete question;

volume of water = 74 mL

Mass of water = 74 g

specific heat of glass = 0.18 cal/g ∙ °C

specific heat of water = 1.0 cal/g ∙ C°

Mass of glass =  x g

Total heat gained by the system = 2000.0cal

Temperature rise = 20.0°C

Heat gained by system = Heat gained  by glass + Heat gained by water

Heat gained by glass = x ×  0.18 × 20

Heat gained by water = 74  ×  1.0 × 20

Hence;

2000 =  (x ×  0.18 × 20) + ( 74  ×  1.0 × 20)

2000 - 1480 =  (x ×  0.18 × 20)

x = 520/3.6

x = 144.4 g

Missing parts;

A glass beaker of unknown mass contains 74.0 ml of water. The system absorbs 2000.0cal of heat and the temperature rises 20.0°C as a result. What is the mass of the beaker? The specific heat of glass is 0.18

cal/g °C, and that of water is 1.0 cal/g °C.​

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Answer:

The answer is D

Explanation:

The chloroplast absorbs sunlight for energy not the cell wall

100000 Pascal

Explanation:

pressure= force/area

Max pressure= force/min area

so f=5

min area= 5×10^-5

5÷5*10^-5 = 100000pascal

Answer:

Explanation:

Ignoring friction and assuming one ramp end rests on level ground.

gravity acceleration acting parallel to the ramp is gsinθ.

F = mgsinθ

mg = 250 N,  sinθ = 3/25

F = 250(3/25)

F = 30 N

A 25 meter long ramp strong enough to hold a person plus a 250 N refrigerator would weigh much more than 250 N.

Answer:

Increases with increase in mass

Explanation:

gravity is proportional to mass and inversely proportional to the square of the distance between them

F = GMm/d²

The patient eating a candy bar instead of fasting for the test should be told

that the test results will be wrong and he may receive a wrong diagnosis.

The medical practitioners told him to fast when coming for a reason and he

forgetting and eating something means the objective for the test may have

been defeated.

This is why it's best to explain to him about the consequences of his actions

which is likely getting a wrong result and diagnosis.

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Answer:

Vertical acceleration 9.8 m/s² downward

Horizontal acceleration 0.0 m/s²

assuming no air resistance.

Answer:

Acceleration due to gravity on a certain planet = 4 m/s²

Explanation:

According to the question,

Weight = 30 N

Mass = 7.5 kg

Let acceleration due to gravity be 'a'

Formula:

Weight = Mass × Acceleration due to gravity

30 = 7.5 × a

a = 30/7.5

a = 4 m/s²