Which BEST explains why rainbows only appear when there is rain and sun? a)The rain needs to dim the light for them to appear. b)The combination of light and water creates a prismatic effect. c)The sun restricts the light rays that impact with the water. d) Heavy rain and little sun produce the strongest rainbows.

Answer:

polar covalent bonding

Explanation:

Water (H2O) is polar because of the bent shape of the molecule. The shape means most of the negative charge from the oxygen on side of the molecule and the positive charge of the hydrogen atoms is on the other side of the molecule. This is an example of polar covalent chemical bonding.

Answer:

D. It is easy to copy.

Explanation:

It is not B, or A, nor C.

Answer:D

Explanation:

Answer:

x = - 8 atau 3

Explanation:

3ˣ² × 3⁵ˣ = 3²⁴

Penarikan:

Mᵃ × Mᵇ = Mᵃ⁺ᵇ

3ˣ² × 3⁵ˣ = 3ˣ²⁺⁵ˣ

Karena itu

3ˣ² × 3⁵ˣ = 3²⁴

3ˣ²⁺⁵ˣ = 3²⁴

x² + 5x = 24

Mengatur kembali

x² + 5x - 24 = 0

Pemecahan dengan faktorisasi

x² - 3x + 8x - 24 = 0

x (x - 3) + 8 (x - 3) = 0

(x + 8) (x - 3) = 0

x + 8 = 0 atau x - 3 = 0

x = - 8 atau x = 3

Karena itu,

x = - 8 atau 3

Answer:

Number of electron wavelength will Double

Explanation:

let the radius = r  and wavelength = λ

when R doubles and  λ ( wavelength ) remains the same

The number of electron electron wavelengths will double as well

Using Bohr's angular momentum quantization to show this

attached below

Answer:

r = 0.0548 m

Explanation:

Given that,

Singly charged uranium-238 ions are accelerated through a potential difference of 2.20 kV and enter a uniform magnetic field of 1.90 T directed perpendicular to their velocities.

We need to find the radius of their circular path. The formula for the radius of path is given by :

[tex]r=\dfrac{1}{B}\sqrt{\dfrac{2mV}{q}}[/tex]

m is mass of Singly charged uranium-238 ion, [tex]m=3.95\times 10^{-25}\ kg[/tex]

q is charge

So,

[tex]r=\dfrac{1}{1.9}\times \sqrt{\dfrac{2\times 3.95\times 10^{-25}\times 2.2\times 10^3}{1.6\times 10^{-19}}}\\\\r=0.0548\ m[/tex]

So, the radius of their circular path is equal to 0.0548 m.

Answer:

uaa,uag,uga

Explanation:

C) OUTER CORE

IT IS THE THICKEST

Answer:

Option A

Explanation:

Nonverbal communications are ambiguous because some times the face expressions (non verbal signals – Sad face or sitting alone gesture of Alejandro) and the verbal signals (communication between Roark and Alejandro) do not match or contradict each other. Some people prefer to believe on their interpretations of the nonverbal  signals as compared to that of the verbal signals

Hence, option A is correct.

Answer:

P = d g h      pressure due to density of liquid of height h

d1 g h1 = d2 g h2       since P1 equals P2

d1 h1 = d2 h2      and the density of Hg is 13.6 times that of water

h2 = (d1 / d2) * h1 = 13.6 * 70 cm =  952 cm or 9.52 m

Answer:

interference

Explanation:

You can just search this.

Answer:

,1) point B

2) point A

I hope it's helps you

Answer:

the speed of the wave on the string is 43.16 m/s

Explanation:

Given;

first harmonic of the wave formed by the string, f₀ = 26 Hz

length of the string, L = 0.83 m

The wavelength for first harmonic of the wave is calculated as;

L = N ----> N

L = λ₀/2

λ₀ = 2L

The speed of the wave on the string is calculated as follows;

v = f₀λ₀

v = f₀ x 2L

v = 26 x 2 x 0.83

v = 43.16 m/s

Therefore, the speed of the wave on the string is 43.16 m/s

Answer:

[tex]\dfrac{dE}{dt} \approx 2.261 \overline {36} \times 10^{12} \ V/ms[/tex]

Explanation:

The parameters given in the question are;

The magnitude of the displacement current density between the plates of a parallel-plate capacitor, J = 19.9 A/m²

We have;

[tex]i_d = \epsilon _0 \times \dfrac{d \Phi_E}{dt} =\epsilon _0 \times A \times \dfrac{d E}{dt}[/tex]

Therefore;

[tex]\therefore \dfrac{dE}{dt} =\dfrac{i_d}{\epsilon _0 \cdot A} =\dfrac{J}{\epsilon_0} = \dfrac{19.9}{8.8 \times 10^{-12}} \approx 2.261 \overline {36} \times 10^{12}[/tex]

Therefore;

[tex]\therefore \dfrac{dE}{dt} \approx 2.261 \overline {36} \times 10^{12} \ V/ms[/tex]

Answer:

They rearrange themselves and join together differently to make new substances called products. The number of atoms of each type is the same before and after a reaction. This means that the total mass of the products is the same as the total mass of the starting substances. In other words, mass is conserved.

Answer:

3

Explanation:

Answer:

a. weathering

Explanation:

weathering is the breakdown of rocks into sediments and soil

Answer:

4.8 km/hr ;

0

Explanation:

Based on information plotted on the graph :

Distance traveled by swimmer C = 2400 m

Travel time of swimmer C = 30 minutes

Converting distance to km:

2400 m = 2400 / 1000 = 2.4 km

Converting time to hour :

30 minutes = 30 / 60 = 0.5 hour

Average speed = Distance traveled / time taken

Average speed = 2.4 km / 0.5 hour = 4.8 km/hr

2.)

Swimmer A's average speed during the period 10 to 20 minutes ;

Change in distance /change in time

(400 - 400) / (20 - 10) = 0

Hence, distance traveled is 0

Answer:

Explanation:

The answer is 75 cm

Answer:

The maximum static frictional force is 40N.

Explanation:

When an object of mass M is on a surface with a coefficient of static friction μ, there is a minimum force that you need to apply to the object in order to "break" the coefficient of static friction and be able to move the object (Called the threshold of motion, once the object is moving we have a coefficient of kinetic friction, which is smaller than the one for static friction).

This coefficient defines the maximum static friction force that we can have.

So if we apply a small force and we start to increase it, the static frictional force will be equal to our force until it reaches its maximum, and then we can move the object and now we will have frictional force.

In this case, we know that we apply a force of 40N and the object just starts to move.

Then we can assume that we are just at the point of transition between static frictional force and kinetic frictional force (the threshold of motion), thus, 40 N is the maximum of the static frictional force.

Of course !

Object-A just has to move twice as fast as Object-B.

Answer:

well i guess i can try...

Explanation:

Volcanoes are a dangerous natural occurance that can greatly effect any ecosystems. There are various effects of volcanoes such as, lava flows, volcanic landslides, mud-flows, and ash flows, which generally result in total obliteration of any ecosystem in their path, they can also have long term beneficial effects to the environment.  One of these long term effects are, the creation of some of the most nutrisous, and fertile soil on earth, causing healthy plants to grow.

Answer:

answer D. all of the above

Answer: according to https://www.doe.virginia.gov When light strikes translucent materials, only some of the light passes through them. The light does not pass directly through the materials. ... Opaque objects block light from traveling through them. Most of the light is either reflected by the object or absorbed and converted to thermal energy.

Explanation:

Answer:

When the rock has fallen 12.0 m;

The kinetic energy of the rock is approximately 3,531.6 J

The potential energy of the rock is approximately 6,768.9 J

Explanation:

The question relates to the characteristic constant total mechanical energy of a body

The mass of the rock that falls, m = 30.0 kg

The height of the cliff from which the rock falls, h₁ = 35.0 m

The required information = The kinetic and potential energy when the rock has falling 12.0 m

The kinetic energy is given by the formula, K.E. = 1/2×m×v²

The potential energy is given by the formula, P.E. = m·g·h

Where;

g = The acceleration due to gravity ≈ 9.81 m/s²

The velocity of the rock after falling through a given height, h is given by the formula, v² = 2·g·Δh

The total mechanical energy of the rock, M.E. = K.E. + P.E. = Constant

At the height of the cliff before falling, Δh =0, therefore v₁ = 0, therefore, K.E. = 1/2×m×v₁² = 0 J

The potential energy at the cliff before the rock begins to fall, P.E. is goven as follows;

P.E. = 30.0 kg × 35.0 m × 9.81 m/s² = 10,300.5 J

At the top of the cliff, M.E. = K.E. + P.E. = 0 J+ 10,300.5 J = 10,300.5 J

∴ M.E. = 10,300.5 J

When the rock has fallen, 12.0 m, Δh = 12.0 m, the speed of the rock, v₂, is given as follows;

v₂² = 2 × 9.81 m/s² × 12.0 m = 235.44 m²/s²

v₂ = √(235.44 m²/s²) ≈ 15.344 m/s

∴ When the rock has fallen 12.0 m, K.E., is given as follows;

K.E. = 1/2×m×v₂²

K.E. = 1/2 × 30.0 kg × 235.44 m²/s² = 3,531.6 J

When the rock has fallen 12.0 m the kinetic energy, K.E. = 3,531.6 J

When the rock has fallen 12.0 m, M.E. = P.E. + K.E.

M.E. = Constant = 10,300.5 J

K.E. = 3,531.6 J

∴ 10,300.5 J = P.E. + 3,531.6 J

P.E. = 10,300.5 J - 3,531.6 J = 6,768.9 J

∴ When the rock has fallen 12.0 m, the potential energy, P.E. = 6,768.9 J.

Answer:

Hubble's Discovery

cosmic microwave background radiation

Answer:

Three main pieces of evidence for the Big Bang theory are the red-shift of light, cosmic background radiation and types of elements.  

Explanation:

Two major scientific discoveries provide strong support for the Big Bang theory: • Hubble's discovery in the 1920s of a relationship between a galaxy's distance from Earth and its speed; and • the discovery in the 1960s of cosmic microwave background radiation.

Answer:

b

Explanation:

the solar system is smaller then nebula nebula is smaller then a galaxie and a galaxie is smaller then a universe

Answer:

(c)Tension = 162 N

(d) Increase

Explanation:

(c)

In order for the cable to lift the plate at uniform velocity, the tension in the cable must be equal to the weight of the plate.

[tex]Tension = Weight = (Density)(Volume)\\Tension = (2.7\ x 10^3\ kg/m^3)(1\ m)(2\ m)(0.03\ m)\\[/tex]

Tension = 162 N

(d)

The tension with upward acceleration will become:

[tex]Tension = m(g+a)\\Tension = mg + ma\\Tension = Weight + ma\\[/tex]

Hence, the tension will increase by an amount equal to "ma".

Answer:

A

Explanation:

magnifying = enlarging something or making it seem bigger