Which of the following involves an endothermic reaction

Answer:

The right approach is "1479°C".

Explanation:

The given values are:

Mass of iron piece,

[tex]m_p=42 \ kg[/tex]

Mass of iron bucket,

[tex]m_I=5 \ kg[/tex]

Mass of water,

[tex]m_w=10 \ kg[/tex]

Iron's specific heat,

[tex]C_I=470 \ J/Kg^{\circ}C[/tex]

Water's specific heat,

[tex]C_w=4186 \ J/Kg^{\circ}C[/tex]

Initial temperature,

[tex]t_I=23^{\circ}C[/tex]

Final equilibrium temperature,

[tex]T=150^{\circ}C[/tex]

Latent heat,

[tex]L_v=2260\times 10^3 \ J/Kg[/tex]

As we know,

The heat lost by the glowing piece of iron will be equal to the heat gain by the iron bucket as well as water, then

⇒ [tex]m_IC_I \Delta T=m_wC_w(100-23)+m_wL_v+m_bC_I(150-23)[/tex]

On substituting the given values, we get

⇒ [tex]42\times 420\times \Delta T=10\times 4186(100-23)+10(2260\times 10^3)+5\times 420(150-23)[/tex]

⇒ [tex]17640 \Delta T=3.22\times 10^6+2.26\times 10^7+2.667\times 10^5[/tex]

⇒          [tex]\Delta T=\frac{2.60867\times 10^7}{17640}[/tex]

⇒          [tex]\Delta T=1479^{\circ}C[/tex]

Answer:

Volume of water displaced = 450 - 375 = 75 ml

Vr = volume of rock = 75 ml

Wr = 9.22 - 7.60 = 1.62 N  weight of 75 ml of rock

Density of rock = 1.62 N / 75 ml = .0216 N / ml

Density of water = 1000 g / 1000 ml = 9.8 N / 1000 ml = .0098 N / ml

Density of rock / density of water = .0216 / .0098 = 2.20

The specific gravity of the rock in the given water volume is 0.2.

The given parameters;

The specific gravity of the rock is calculated as follows;

[tex]S.G = \frac{weight \ in \ air}{Weight \ in \ water} \\\\S.G = \frac{450 - 375}{375} \\\\S.G = 0.2[/tex]

Thus, the specific gravity of the rock in the given water volume is 0.2.

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Answer:

trur

Explanation:

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Answer:

when water hits a metal surface it alongside oxygen have a chemical reaction making Hydrogenated Iron Oxide

Explanation:

what i remember from 7th grade

Answer:

J = 357.5 kg*m/s

Explanation:

       [tex]p_{o} = m*v_{o} = 55 kg * (-3.0 m/s) (1)[/tex]

       [tex]p_{f} = m*v_{f} = 55 kg * (3.5 m/s) (2)[/tex]

      [tex]J = p_{f} - p_{o} = m* (v_{f} -v_{o}) = 55 kg* (3.5m/s- (-3.0m/s)) = 357.5 kg*m/s (3)[/tex]

Answer:

Earth's gravity

Explanation:

hope this helps

Answer:

the earth gravity

Explanation:

Gravitational attraction provides the centripetal force needed to keep planets in orbit around the Sun and all types of satellite in orbit around the Earth. The Earth's gravity keeps the Moon orbiting us.

Answer:

a. 0.332 W/m² b. 11.2 V/m c. 15.8 V/m

Explanation:

(a) the average intensity of the light,

Intensity, I = P/A where P = average power = 150.0 W and A = area through which the power emits = 4πr² where r = distance from bulb = 6 m.

So, I = P/A = P/4πr²

Substituting the values of the variables into the equation, we have

I =  P/4πr²

I =  150.0 W/4π(6 m)²

I =  150.0 W/4π(36 m²)

I =  150.0 W/452.39 m²

I =  0.332 W/m²

(b) the rms value of the electric field,

Since Intensity, I = E²/cμ₀ where E = rms value of electric field, c = speed of light = 3 × 10⁸ m/s and μ₀ = permeability of free space = 4π × 10⁻⁷ H/m.

Making E subject of the formula, we have

E² = Icμ₀

E = √(Icμ₀)

Since I = 0.332 W/m², substituting the other terms into the equation, we have

E = √(0.332 W/m² × 3 × 10⁸ m/s × 4π × 10⁻⁷ H/m.)

E = √(0.332 W/m² × 3 × 10⁸ m/s × 4π × 10⁻⁷ H/m.)

E = √(12.5 × 10)

E = √125 V/m

E = 11.18 V/m

E ≅ 11.2 V/m

(c) the peak value of the electric field.

The peak value of electric field, E' is gotten from E = E'/√2 where E = rms value of electric field.

So, E' = √2E

= √2 × 11.2 V/m

= 15.81 V/m

≅ 15.8 V/m

Answer:

Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s

Explanation:

Impulse is equal to the product of force and time

Here

Density of car =  [tex]0.54[/tex]  g/mL

Volume of car [tex]= 38.2[/tex] mL

Mass of the car is equal to the product of density and volume of car

Mass of the car [tex]= 0.54 * 38.2[/tex] [tex]= 20.628[/tex] grams

Acceleration of the car is [tex]10[/tex] m/s^2

Force is equal to product of mass and acceleration

F = [tex]20.628 * 10 = 206.28[/tex] g .m/s^2

Impulse = F * t

Impulse = [tex]206.28 * 10 = 2062.8[/tex] g.m/s

Answer:

B

Explanation:

Answer:

it is coice A and choice D

Answer:

5.94 N·s

Explanation:

F = 132 N

t = 0.045 s

Impulse = Ft = (132 N)(0.045 s) = 5.94 N·s

Answer:

v = 9.04 m / s

Explanation:

For this exercise we can use the relation that the work of the non-conservative force (friction) is equal to the variation of the mechanical energy of the system.

          W = Em_f - Em₀         (1)

Starting point. Lower slope

        Em₀ = K = ½ m v²

highest point. Where is the skier at a height h

        Em_f = U = m g h

The work of rubbing

        W = -fr x

the negative sign is because the friction force opposes the movement.

Let's set a reference system where the x axis is parallel to the slope and the y axis is perpendicular

let's use trigonometry to break down the weight

        cos θ = W_y / W

        sin θ = Wₓ / W

        W_y = W cos θ

        Wₓ = W sin θ

Y axis

        N - Wₓ = 0

        N = mg sin  θ

X axis

         fr = m a

the friction force has the expression

         fr = μ N

         fr = μ mg sin θ

we look for the job

         W = - μ mg sin θ  x

where x is the distance along the slope

we substitute in 1

         -μ mg sin θ x = mg h - ½ m v²

let's use trigonometry to find the distance x

        tan 30 = h / x

        x = h / tan 30

we substitute

          -   [tex]\mu \ mg \ sin \theta \ \frac{h}{tan 30} \ x[/tex] = m gh - ½ m v²

we use  

          tan 30 = sin30 / cos30

          v² = 2g h + 2 μ g h cos 30

          v = [tex]\sqrt{ 2gh \ (1+ cos 30}[/tex]

let's calculate

          v = [tex]\sqrt{ 2 \ 9.8 \ 4 \ (1 + 0.05 \ cos \ 30)}[/tex]

          v = 9.04 m / s

Answer: The president submits a budget to Congress by the first Monday in February every year. The budget contains estimates of federal government income and spending for the upcoming fiscal year and also recommends funding levels for the federal government.

Explanation:

Answer: The president submits a budget to Congress by the first Monday in February every year. The budget contains estimates of federal government income and spending for the upcoming fiscal year and also recommends funding levels for the federal government.

Your welcome!! :)

Answer:

The answer is option D. +f

Option D represents a concave lens. There are two types of lenses, one is a concave lens while the other is the convex lens.

A concave lens deviates a direct beam from the source into a reduced form.  At minimum, one interior face of concave lenses is curved.

Because it is curved round inwards at the center and bulges outwards through the edges, causing the light to diverge, a concave lens is also known as a diverging lens.

It forms an upright , virtual picture both real and virtual pictures are formed from the concave lens.

The image formed from the positive side of the focus of the lens.+f shows the positive side of the focus of the lens.f is the focal length.

Hence, option D represents a concave lens

To learn more about the concave lens, refer to the link;

https://brainly.com/question/2919483

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Answer: A. The reactants must collide in a certain way for the reaction to  occur.

Explanation: I did the quiz :)

Answer:

A) The reactants must collide in a certain way for the reaction to

occur.

Explanation:

A.P.E.X

Answer:

true

Explanation:

i think its true beacuse water can cause electricity

pls let me know if corrct

if yes pls mark brainlest

Answer:

leader give enthusiasm and strength power to country they reflect to. be a successful and hyperbolic

Explanation:

leader is the main king of the country they reflect them to be honourable and be confident that is the way to get key on a typical African

Answer:

Electromanetic

Explanation:ESPERO TE AYUDE

Answer:

The answer is "892.90 N"

Explanation:

Following are the solution to these question:

Calculating the vertical force of the summation that is equal to zero:

[tex]\to TL \cos 65 + TR \cos 80 -520 = 0\\\\\to 0.4226\ TL + 0.1736\ TR = 520\\[/tex]

Calculating the sum of horizontal forces that is equal to zero:

[tex]\to TL\sin 65 - TR \sin 80 = 0 \\\\\to 0.9063TL - 0.9846TR = 0\\\\\to TL = (\frac{0.9846}{0.9063})\ TR \ \ = 1.0866\ TR\\\\\to 0.4226(1.0866) \ TR +0.1736\ TR =520 \ N\\\\\to 0.6328 \ TR = 520 \\\\\to TR = 821.74 \ N \\\\\to TL = 1.0866 \times 821.74 = 892.90\ N[/tex]

Answer:

The nephew

Explanation:

The nephew has a seeing eye dog which means the nephews tracks are the dogs tracks, and the dog tracks are not covered by anything which means the dog was last and stole the butterfly.

Hope this helps!

Answer:

16.67 m/s

Explanation:

Let that velocity be v.

Using conservation of momentum:

Initial momentum = final momentum

momentum of car1 = momentum of cars

mass1 x velocity1 = (m1 + m2)v

1500*30 = (1500 + 1200)v

45000/2700 = v

16.67 m/s = v

Answer:

10

Explanation:

i dont know this is right answer

0.35

0.91

1.26

1.57

Explanation:

I did it on ed2020 and got it correct

Answer:

h = 47 m

Explanation:

First, we will calculate the force on the cord due to the weight:

[tex]Force = F = Weight\\F = mg\\F = (79\ kg)(9.81\ m/s^2)\\F = 775\ N[/tex]

Now, we will calculate the elongation by using Hooke's Law:

[tex]F = k \Delta x[/tex]

where,

k = spring constant = 43 N/m

Δx = elongation = ?

Therefore,

[tex]775\ N = (43\ N/m)\Delta x\\\\\Delta x = \frac{775\ N}{43\ N/m}\\\\\Delta x = 18\ m\\[/tex]

So, the final length of the cord will be:

[tex]Final\ Length = Initial\ Length + \Delta x\\Final\ Length = 35\ m + 18\ m\\Final\ Length = 53\ m\\[/tex]

Hence, the height from water (h) can be found using the following formula:

[tex]h = Height\ of\ Bridge - Final\ Length\ of\ cord\\h = 100\ m - 53\ m\\[/tex]

h = 47 m

Answer:

is point 2

Explanation:

There is a good cause for concern that technology will create social isolation

Answer:

the nephew

Explanation:

because we need to First find the trails that is on top of all the others in order to find who was the last to leave, since the person that was last to leave would most likely step on another person's trail that has been theirs before them.

by looking at this picture I noticed that the butler's footprint was the latest one but the dogs footprint steps over it therefore making it the last to leave, and the person who owns a dog is her nephew so therefore the nephew is the one that stole the butterfly trophy.

Answer:

[tex]1.5 \times 10^{-5} \mathrm{~T}[/tex].

Explanation:

Power carried by the line [tex]=P=450 \mathrm{MW}=450 \times 10^{6} \mathrm{~W}[/tex]

Voltage across the line Volts

Current flowing in the line =i

Size of magnetic field =B

Distance from the line

Formula Used:

Current flowing is given as

[tex]i=\frac{P}{\Delta V}[/tex]

Magnetic field by the current carrying wire is given as

[tex]B=\left(\frac{\mu}{4 \pi}\right)\left(\frac{2 i}{r}\right)[/tex]

Inserting the values

 [tex]B=\left(10^{-7}\right)\left(\frac{2(1500)}{(20)}\right) \\ B=1.5 \times 10^{-5} \mathrm{~T}[/tex]

Conclusion:

Thus, the magnetic field comes out to be [tex]1.5 \times 10^{-5} \mathrm{~T}[/tex].

Answer:

Birds in different areas were exposed to different food sources.

Explanation:Im almost 100 percent this is it.

Answer:

the answer is B

Explanation:

i did test on preformance