PLEASE HELPPPPPPPPPP​

Answer:

B

Explanation:

water do not have a solid shape and that makes it take to shape of a container etc

Answer:

D. Requiring a lot of energy to change temperature

Explanation:

because im right n ur wrong

Answer:

a) The heat input per cycle is 2857.143 joules.

b) The temperature of the low-temperature reservoir is 49.655 °C.

Explanation:

a) The efficiency of the Carnot engine is defined by the following formula:

[tex]\eta_{th} = 1-\frac{T_{L}}{T_{H}} = 1 - \frac{Q_{L}}{Q_{H}}[/tex] (1)

Where:

[tex]T_{L}[/tex] - Low temperature reservoir, in Kelvin.

[tex]T_{H}[/tex] - High temperature reservoir, in Kelvin.

[tex]Q_{L}[/tex]  - Heat output, in joules.

[tex]Q_{H}[/tex] - Heat input, in joules.

[tex]\eta_{th }[/tex] - Engine efficiency, no unit.

If we know that [tex]\eta_{th} = 0.3[/tex] and [tex]Q_{L} = 2000\,J[/tex], the heat input of the Carnot engine is:

[tex]\eta_{th} = 1 - \frac{Q_{L}}{Q_{H}}[/tex]

[tex]\frac{Q_{L}}{Q_{H}} = 1 - \eta_{th}[/tex]

[tex]Q_{H} = \frac{Q_{L}}{1-\eta_{th}}[/tex]

[tex]Q_{H} = \frac{2000\,J}{1-0.3}[/tex]

[tex]Q_{H} = 2857.143\,J[/tex]

The heat input per cycle is 2857.143 joules.

b) If we know that [tex]T_{H} = 461.15\,K[/tex] and [tex]\eta_{th} = 0.3[/tex], then the temperature of the low-temperature reservoir:

[tex]\eta_{th} = 1 - \frac{T_{L}}{T_{H}}[/tex]

[tex]\frac{T_{L}}{T_{H}} = 1 - \eta_{th}[/tex]

[tex]T_{L} = T_{H}\cdot (1-\eta_{th})[/tex]

[tex]T_{L} = (461.15\,K)\cdot (1-0.3)[/tex]

[tex]T_{L} = 322.805\,K[/tex]

[tex]T_{L} = 49.655\,^{\circ}C[/tex]

The temperature of the low-temperature reservoir is 49.655 °C.

Answer:

Explanation:

In a Solid sphere; the moment of inertia around its geometrical axis can be expressed by using the formula:

[tex]\mathtt{I_s = \dfrac{2}{5} M_s R^2_s}[/tex]

For the solid disk; the moment of inertia around the central axis is:

[tex]\mathtt{I_D= \dfrac{1}{2}M_DR_D^2}[/tex]

Suppose [tex]M_D = M_S[/tex]; then we can say both to be equal to M

As well as [tex]R_D = R_S[/tex]; then that too can be equal to R

Now;

[tex]\mathtt{I_s = \dfrac{2}{5} M R^2} --- (1)[/tex]

[tex]\mathtt{I_D= \dfrac{1}{2}MR^2}---(2)[/tex]

Multiplying equation (1) by 2, followed by dividing it by 2; we have:

[tex]\mathtt{I_s= \dfrac{2}{5}MR^2} \times \dfrac{2}{2}[/tex]

[tex]I_s = \dfrac{4}{5} \times \dfrac{1}{2}MR^2 \\ \\ I_s = \dfrac{4}{5}\times I_D \\ \\ I_s > I_D[/tex]

Answer:

resonance is when a body is made to vibrate with the frequency of another body without touching it.

Explanation:

example of destructive: soldiers matching on a bridge unanimously can make the bridge collapse.

Answer:hi

i like ears

and lemon

and poetry

Explanation:

Answer:

Photosynthesis, the process by which green plants and certain other organisms transform light energy into chemical energy. ... During photosynthesis in green plants, light energy is captured and used to convert water, carbon dioxide, and minerals into oxygen and energy-rich organic compounds.

Explanation:

thank me later

Answer:

Only a decreasing gravitational force that acts downward

Explanation:

The gravitational force is the gravitational pull which attract a mass of smaller size by the mass of a bigger size.  It is the force which attract two masses close to each other.

In the context, when a ball is tossed up from the surface of an asteroid that have no atmosphere, the ball rises up and then falls back to the surface of the asteroid. The ball falls back because the gravitational pull of the asteroid pulls back the ball to its surface. Thus a decreasing gravitational force acts on the ball in the downward direction while the ball is in its way up.  

White Dwarf Stage

Answer:

I = 1.58 x 10⁻³ watt/m²

Explanation:

Here, we will use the following formula:

[tex]\beta = 10\ log_{10}(\frac{I}{I_o})[/tex]

where,

β = decibel level = 92 dB

I = Intenisty of sound in watt/m² = ?

I₀ = reference intensity = 10⁻¹² watt/m²

Therefore,

[tex]92\ dB =10\ log_{10}(\frac{I}{10^{-12}\ watt/m^2} )\\\\[/tex]

[tex]10^{9.2} = \frac{I}{10^{-12}}\ watt/m^2\\\\I = (1.58\ x\ 10^9)(10^{-12}\ watt/m^2)[/tex]

I = 1.58 x 10⁻³ watt/m²

Answer:

yes

Explanation:

this means the answer is yes

Answer:

Cause it gives us internet

forces: forces applied to an object in opposite directions that are not equal in size. Unbalanced forces result in a change in motion. friction: the force that opposes the motion or tendency toward motion of two objects that are in contact.

Answer:

Option C, acting as waves and particles

Explanation:

Light has dual nature  because it acts both as a wave and particle. It has high energy particle i.e photons and it also behave as an electromagnetic wave. This property of light is studied under the quantum mechanics. Einstein also proved that light is a stream of photons possessing both electrical and magnetic properties.

Hence, option C is correct

Answer: The frequency of a pendulum is [tex]0.2 s^{-1}[/tex].

Explanation:

Time period is defined as the time required to produce complete wave.

As we know that the frequency and time are inversely proportional to each other.

That means,

[tex]\nu =\frac{1}{T}[/tex]

Where,

[tex]\nu[/tex] is frequency of pendulum

T is time period

Given:

Time period = 5 seconds

Now putting all the given values in the above formula, we get the frequency of the pendulum.

[tex]\nu =\frac{1}{T}\\\\\nu =\frac{1}{5s}\\\\\nu =0.2s^{-1}[/tex]

Therefore, the frequency of a pendulum is [tex]0.2 s^{-1}[/tex].

Answer:

8 units

Explanation:

From the question given above, the following data were obtained:

Initial force (F₁) = 72 units

Initial distance apart (r₁) = r

Final distance apart (r₂) = tripled = 3r

Final force (F₂) =.?

The final force between the two objects can be obtained by using the following formula:

F₁r₁² = F₂r₂²

72 × r² = F₂ × (3r)²

72r² = F₂ × 9r²

Divide both side by 9r²

F₂ = 72r² / 9r²

F₂ = 8 units

Therefore, the final force between the two objects is 8 units

Answer:

The battery is charging and has a current of 2Amps passing through.

Explanation:

Given;

EMF of the battery, E = 12 V

internal resistance, r = 0.5 ohms

terminal voltage of the battery, ΔV = 13 volts

When the terminal voltage is greater than the EMF of the battery, the battery is being charged, allowing currents to pass in a reverse direction.

ΔV = E - Ir

ΔV - E = -Ir

13 - 12 = -0.5I

1 = -0.5I

I = 1 / -0.5

I = -2 A

The negative sign indicates the reverse direction of the current.

Therefore, the battery is charging and has a current of 2Amps passing through.

Answer:

THE NUMBER OF PROTON IS EQUAL TO THE NUMBER OF ATOMIC NUMBER(Z) IN AN ATOM

Explanation:

PLZ MARK ME BRAINLIEST

Answer:

Explanation:

The number of proton is equal to the number of electron in an atom.

Answer:

Please find the complete question in the attached file.

Explanation:

In this statement, the weak electromagnetic field that has been used when with the range of resistance to start measuring the mobility of even an ion with both the counter-charge utilization as well as the DC is the potential for using so that we can always obtain a desired electrical field and modify the drift chamber lengthy and gas pressures buffered.

Answer:

i'd say 1kg-----5m-----5kg but im not to sure

Explanation:

Answer:

here's the pdf for it

IB QuestionbankExplanation:

Answer:

B. They are inversely proportional to each other

[tex] \frac{momentum}{time} = force \\ \\ \frac{mass \times velocity}{time} = force \\ \\ \frac{mass \times velocity}{time} = mass \times acceleration[/tex]

Answer:

  [tex]\frac{T}{T_o} = ( 1 + \frac{1}{n} )^2[/tex]

Explanation:

This is a string resonance exercise, the wavelengths in a string held at the ends is

          λ = 2L₀ / n

where n is an integer

the speed of the wave is

           v = λ f

            f = v /λ

the speed of the wave is given by the characteristics of the medium (string)

           v = [tex]\sqrt{\frac{T}{\mu } }[/tex]

we substitute  

            f = [tex]\frac{n}{2L_o} \ \sqrt{\frac{T}{\mu } }[/tex]

to obtain the following harmonic we change n → n + 1

            f’ =  [tex]\frac{n+1}{2L_o} \ \sqrt{\frac{T_o}{\mu } }[/tex]

In this case, it tells us to change the tension to obtain the same frequency.

            f ’= \frac{n}{2L_o} \  \sqrt{\frac{T}{\mu } }

how the two frequencies are equal

         [tex]\frac{n+1}{2L_o} \sqrt{\frac{T_o}{ \mu } } = \frac{n}{2L_o} \sqrt{\frac{T}{\mu } }[/tex]

           (n + 1) [tex]\sqrt{T_o}[/tex] = n [tex]\sqrt{T}[/tex]

             [tex]\frac{T}{T_o} = ( \frac{n+1}{n} )^2[/tex]

             [tex]\frac{T}{T_o} = ( 1 + \frac{1}{n} )^2[/tex]

this is the relationship of the voltages to obtain the following harmonic,

Solution :

We all know that a bar magnet have two poles, the north pole and the south pole. These poles interacts with each other. The ends of the magnets having similar poles will push each other away while the poles with like charges will pull each others towards it.

The compass needle is also a magnet having south polarity as well as north polarity. When the compass needle is close to the bar magnet, it is opposite to the poles or along the poles. The compass needle shows the direction or is pointed towards the north. So when the compass needle is placed near the north pole of the bar magnet, the pointer of the compass needle points towards the north, i.e. it gets deflected because of he like charges. And when it is placed near the south pole of the magnet, it gets attracted towards it and is pointed towards the pole.

Now as we move the compass needle from the poles to the region that is between the poles, the compass needle pointer points towards the north direction every time. It show a deflection always. If we place the magnetic lines, we will see that the magnetic lines will exit from the north poles and enters the south pole of the bar magnet.  

Answer:

 Q / m = 8.61 10⁻¹¹ C / kg

Explanation:

For this exercise we use the gravitational force of attraction

     [tex]F_g = G \frac{m_1m_2}{r^2}[/tex]

the electric force

     [tex]F_e = k \frac{q1q2}{r^2}[/tex]

indicate that the two forces are equal

     G m₁ m₂ / r² = k q₁ q₂ / r²

they also say that the two masses are equal and the two charges are equal

     G m² = k Q²

     Q / m =  [tex]\sqrt{\frac{G}{k} }[/tex]

we calculate

      Q / m = [tex]\sqrt{\frac{6.67 \ 10^{-11} }{8.99 \ 10^9} }[/tex]

      Q / m = [tex]\sqrt{ 0.7419 \ 10 ^{-20}}[/tex]

       Q / m = 0.861 10⁻¹⁰

       Q / m = 8.61 10⁻¹¹ C / kg

area= length × length

area = 4m × 9m

ans 36

Answer:

F' = 800 N

Explanation:

The electrical force between charges is 400 N.

The electrical force between two charges is given by :

[tex]F=k\dfrac{q_1q_2}{r^2}[/tex]

If q₁' = 2q₁, new force becomes,

[tex]F'=k\dfrac{q_1'q_2'}{r^2}\\\\F'=k\dfrac{2q_1\times q_2}{r^2}\\\\F'=2\times F\\\\F'=2\times 400\\\\F'=800\ N[/tex]

So, the new force becomes 800 N.