valancy of an atom is +2. what does it mean. ​

Explanation:

Volume is the quantity of three-dimensional space enclosed by a closed surface

The si unit of mass is kilogram (kg) and the si unit of length is metre(m)

Answer:

option a negative to positive

Explanation:

The flow of electrons is termed electron current. Electrons flow from the negative terminal to the positive. Conventional current or simply current, behaves as if positive charge carriers cause current flow. Conventional current flows from the positive terminal to the negative

brainliest plsss

Answer:

Explanation:

It was Newton's genius that saw that it was true. He also realized that if it was true, the motion the earth experience would be unmeasurably small, especially in his time. Their instruments were just not good enough: crude and too approximate would be better descriptions.

Answer:

Remember the relation:

Speed*Time = Distance.

We can estimate that the speed at which an earthquake "moves", in the surface, is:

S = 6km/s  (this is a low estimation actually)

Then if the wave is detected 12.5 minutes after the earthquake, we know that it traveled for 12.5 minutes before reaching the detector.

So we know the speed of the wave and the time it took to reach the detector, then we can use the equation:

Speed*Time = Distance.

to find the distance.

First, we should write the time in seconds

we know that:

1 min = 60 s

then:

12.5 min = 12.5*(60 s) = 750 s

Then, the wave traveled with a speed of 6 km/s for 750 seconds until it reached the detector, then the distance that it traveled is:

(6km/s)*750s = 4500 km

The distance between the detector and the site of the quake is around 4500 km.

Answer:

38500

Explanation:

I looked it up so it may be wrong

Answer:

ccccccccc or bbbbbbb or aaaaaaaa or ddddddd

Answer:

d

Explanation:

I'm not perfectly sure so check again

Momentum is a quantity that we can say is typically conserved in collisions.

Momentum is the quantity that that we see typically conserve in the collision,therefore the correct answer is the option A

It is the type of collision in which the total momentum  as well as the kinetic energy on the system is conserved .The momentum before the collision is equal to the momentum after the collision in other words one can say in the elastic collision momentum of the quantity is conserved.

In the inelastic collision the momentum is conserved but the kinetic energy of the quantity is not conserved.

Momentum of a quantity is conserved irrespective of the type of collision  whether it will be elastic collision or inelastic collision the momentum of the quantity will always be conserved.

Hence,we can say that momentum is the quantity that is conserved in collision,The correct answer for the given problem is option A.

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Answer:

Explanation:

The heat from the Sun gets to the surface of the Earth by radiation and not by convection because:

i. Radiation does not require material medium for its propagation: Since the space between the Sun and Earth is a vacuum ( i.e it is an empty space), then the only method for the heat from to Sun to get to the Earth is by radiation. This method does not require a material medium, while convection is a method that requires material medium for its propagation.

ii. Radiation occurs without heating the intervening medium: During the propagation of the heat from the Sun to the Earth, the space between the two heavenly bodies is not heated up. Some fraction of the heat after hitting the surface of the Earth get reflected back into the Earth's atmosphere. While in convection, the medium would have been heated up in the process.

Answer:

Explanation:

We are basically needing to solve for the time in the equation d = rt, where d is the distance around Mars (aka the circumference), r is the velocity, and t is time. We need to find the circumference and the velocity. We will begin with the velocity.

Because the gravitational attraction between Phobos and Mars provides the centripetal acceleration necessary to keep Phobos in its (sort of) circular path, the equation we use for this is:

[tex]F_g=F_c[/tex] which says that Force supplied by gravity is equal to the centripetal force. Expanding that:

[tex]\frac{Gm_{Phobos}m_{Mars}}{r^2}=\frac{m_{Phobos}v^2}{r}[/tex]

When we move that around mathematically to solve for the velocity value, what we end up with is:

[tex]v=\sqrt{\frac{Gm_{Mars}}{r}[/tex] and filling in:

[tex]v=\sqrt{\frac{(6.67*10^{-11})(6.42*10^{23})}{9.38*10^6} }[/tex] and we get that

v = 2100 m/s

Now for the circumference:

C = 2πr and

C = 2(3.1415)(9.38 × 10⁶) so

C = 5.9 × 10⁷

Putting that all together in the C = vT equation:

5.9 × 10⁷ = 2100T so

T = 2.8 × 10⁴ sec or 7.8 hours

Answer:

is 10³

Explanation:

cuz the formula of KE is 1/2mv²

covert 50g to kg first then plug in the formula

1/2 × 0.05 × 200 = 10³ J

The height of the window above the ground is 11.025m

The first step is to write out the parameters given in the question

U(initial velocity)= 0

Time= 1.5 seconds

Acceleration due to gravity= 9.8

Therefore the height of the window can be calculated as follows

S= ut + 1/2gt²

= 0(1.5) + 1/2(9.8)(1.5²)

= 0 + 1/2(9.8)(2.25)

=  1/2(22.05)

= 0.5×22.05

= 11.025

Hence the height of the window above the ground is 11.025m

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Answer:

D

Explanation:

i just did it trust me

Answer:

the magnetic compass is used to determine direction because it is one of the most accurate form of magnet as we already know that a freely suspended magnet always faces towards north direction and south direction

Answer:

Yes, this is true.

-- While the apple is falling, the same gravitational force acts on both the apple and the Earth.

-- The mass of the apple is somewhere in the neighborhood of 1/4 kg.

-- The mass of the Earth is about 5.972 x 10²⁴ kg.

-- Since the Earth has roughly 2.389 x 10²⁶ times as much mass as the apple has, the apple has roughly 2.389 x 10²⁶ greater acceleration than the Earth has, and moves roughly 2.389 x 10²⁶ times as far down as the Earth moves up, before they smack together.

-- That's why you don't notice the Earth's motion.

-- Also, you're standing on the Earth, moving up with it, toward the apple.  Maybe it would be different if you were sitting on the apple, riding it down to the ground, and you were able to notice the motion of the ground coming up to meet you at a speed that's 0.00000000000000000000000000419 of YOUR speed.  

Answer From Gauth Math

Part A - The apparent displacement of the mark is 4 cm.

The refractive index of a material, n = real depth, D/apparent depth, L.

So, n = D/L

Since the refractive index of the triangular glass prism is 1.5, n = 1.5. Also, the triangular glass prism is 12 cm thick and placed on a mark on a piece of paper resting on a horizontal bench. So, the real depth of the mark on the piece of paper through the triangular prism is D = 12 cm and its apparent depth is L.

Since n = D/L,

making L, subject of the formula, we have

L = D/n

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

L = D/n

L = 12 cm/1.5

L = 8 cm

so, the apparent depth of the mark is 8 cm.

So, the apparent displacement of the mark is d = D - L = 12 cm - 8 cm = 4 cm

Thus the apparent displacement of the mark is 4 cm.

Part B - The refractive index of water, n = 1.33.

The refractive index of a material, n = real depth, D/apparent depth, L.

So, n = D/L

Since the depth of water in the jar is 24 cm, the real depth, D = 24 cm.

Also, the bottom of the jar appears to be raised by 6 cm. So, the apparent depth, L = 24 cm - 6 cm = 18 cm

Since n = D/L, the refractive index of water n = D/L

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

n = D/L

= 24 cm/18 cm

= 1.33

So, the refractive index of water, n = 1.33.

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[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]

We know

[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]

[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]

[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]

Answer:

Current- the flow of free charges, such as electrons and ions

Drift velocity- the average speed at which these charges move

Answer:

An electric current is the stream of changed particals, such as electrons & ions, moving through an electrical conductor.

The average velocity attained bycharged partical ,such as electrons,in a material due to electric fields

Sabemos todo material tiene asociado un coeficiente de difracción n.

De tal forma que la velocidad de una onda electromagnetica que viaja a travez de dicho material, será:

v = c/n

donde c es la velocidad de la luz.

Con la información dada, podremos concluir que el coeficiente de difracción del medio Q es dos veces el del medio P.

Ahora veamos como llegamos a esto:

Sabemos que en el medio P, la onda recorre una distancia 8*D en un tiempo 4*T

entonces la velocidad de la onda en el medio P es:

[tex]V_p = \frac{8*D}{4*T} = 2*\frac{D}{T}[/tex]

Mientras que en el medio Q, recorre una distancia 4*D en un tiempo 4*T, por lo que la velocidad en el medio Q será:

[tex]V_Q = \frac{4*D}{4*T} = \frac{D}{T}[/tex]

Podemos ver que:

[tex]V_P = 2*V_Q[/tex]

Reescribiendo las velocidades como el cociente entre la velocidad de la luz y el correspondiente coeficiente de difracción obtenemos:

[tex]\frac{c}{n_P} = 2*\frac{c}{n_Q} \\\\n_Q = 2*n_P[/tex]

Es decir, podemos concluir que el coeficiente de difracción del medio Q es dos veces el del medio P.

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Answer:

I THINK IT'S D....

HOPE SO

Answer:

if buoyant force is equal is equal to the weight of body then our body float. if density of our body is less than density of liqiud then our body float in water.

Answer:

A

Explanation:

i think a is the answer because if you take an example of group 1 and 2 metals on the periodic table you will notice that they are highly reactive but they have a few electrons in their outer most shells.

I hope this helps

Answer:

42g

Explanation:

the mass of a body is given by

m=weight/gravity

=420/10

=42

I hope this helps

Explanation:

Density is mass in grams over volume in cubic centimeters.

So it is

[tex]\frac{4g}{5cm^{-3} }[/tex]  =  0.8 g/cm[tex]^{3}[/tex]  

The unit is grams per cubic centimeter.

NB - density can also be kilograms over cubic meters

Our sun is 27 million times larger than our moon. Based on its mass, the sun's gravitational attraction to the Earth is more than 177 times greater than that of the moon to the Earth. If tidal forces were based solely on comparative masses, the sun should have a tide-generating force that is 27 million times greater than that of the moon. However, the sun is 390 times further from the Earth than is the moon. Thus, its tide-generating force is reduced by 3903, or about 59 million times less than the moon. Because of these conditions, the sun’s tide-generating force is about half that of the moon.