7th grade science i mark as brainliest

Answer: A: electron shells outside a central nucleus

B: hard, indivisible sphere

C: mostly empty space

Which list of atomic model descriptions represents

the order of historical development from the earliest

to most recent?

Explanation:

3

Atomic models have been proposed throughout history describing the possible arrangements of different particles inside the atoms.

Thus, the correct order of atom model is B C A. Hence, the correct answer is option C.

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Using the experimental result greatest electric fleld can be found in practical application.

According to the problem,

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Answer: see below

Explanation:

The intial speed is u=0\(\frac{m}{s}\)

The acceleration is a= 3.3\(\frac{m}{s}^2\)

The distance is s=60m

Apply the equation of motion

\(v^{2}\)=\(u^{2}\)+2as

So,

\(v^{2}\)=0+2*3.3*60=396

v=\(\sqrt{396}\) = 19.89 m/s ≈20 m/s

Applying the equation of motion

v=u+at

t= \(\frac{v-u}{a}\) =\(\frac{19.89-0}{3.3}\) = 6.02seconds

Answer:

The hypotenuse is 3.68

3.682 = 2.852 + x2

14.8669 = 8.1225 + x2

6.7444 = x2

2.59699827 ≈ x

The monkey can climb about 2.6 feet up the pole

Explanation:

The amount of power required to move the 120 Kg person to a distance of 35 m in 150 s is 274.4 W

Power is simply defined as the rate at which work is done. It can be expressed mathematically as

Power (P) = work (W) / time (t)

But

Work = force (F) × distance (d)

Therefore,

P = Fd / t

With the above formula, we can obtain the power as follow:

P = Fd / t

P = (1176 × 35) / 150

P = 41160 / 150

P = 274.4 W

Thus, the power is 274.4 W

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Assuming the surface is frictionless, the energy lost to friction would be 0 Joules.

Friction is the force that resists motion between two objects that are in contact with each other. In the experiment, friction is the force that resists the motion of the second spring as it compresses a distance of d2/2. Since the surface is rough, it provides a strong resistance to the motion of the spring, thus leading to a loss of energy.

However, if the surface had been frictionless, then the second spring would have compressed a distance of d2, as there would be no resistance to its motion. This means that no energy would have been lost to friction, as there would not have been any friction present in the system.

In conclusion, friction is the force that is responsible for the loss of energy in this experiment. When the surface is rough, the friction between the surface and the second spring is strong, leading to a loss of energy. However, when the surface is frictionless, the friction between the surface and the second spring is not present, thus no energy is lost to friction.

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Answer:

Sonam will jump further than wangchuck

Answer:

C=A>B>E>D

Explanation:

Most organisms are unable to take the element nitrogen from the atmosphere. Nitrogen is an element that makes up 78% of the Earth's atmosphere. However, most organisms are unable to utilize atmospheric nitrogen. Atmospheric nitrogen is transformed into a usable form by nitrogen fixation.

Nitrogen fixation is the process of converting atmospheric nitrogen into a usable form. Biological nitrogen fixation is carried out by bacteria that are found in the soil, and it is a crucial part of the nitrogen cycle. Nitrogen-fixing bacteria can be found in the root nodules of some plants, such as legumes, where they convert atmospheric nitrogen into ammonia. Ammonia is converted into nitrates by other bacteria, making it accessible to plants. As a result, these plants have a higher nitrogen content than non-legumes, and they can enrich the soil by releasing nitrogen when they die. Overall, nitrogen fixation is a crucial process for the survival of many organisms, as it provides a way to convert atmospheric nitrogen into a usable form.

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To determine the map distances between E and F, E and G, and F and G, we can use the formula:
Map distance = (Number of recombinant progeny / Total number of progeny) * 100

Map distance between E and F:
Number of recombinant progeny (eFG + Efg + eFg + EFG) = 298 + 302 + 99 + 91 = 790
Total number of progeny = Sum of all progeny = 298 + 302 + 99 + 91 + 92 + 88 + 19 + 16 = 1005
Map distance between E and F = (790 / 1005) * 100 = 78.6 mn (rounded to the nearest whole number)
Map distance between E and G:
Number of recombinant progeny (eFG + EFg + EFG + efG) = 298 + 92 + 19 + 88 = 497
Total number of progeny = 1005 (same as before)
Map distance between E and G = (497 / 1005) * 100 = 49.35 mn (rounded to the nearest whole number)
Map distance between F and G:
Number of recombinant progeny (EFG + efG + EFG + efg) = 91 + 88 + 19 + 16 = 214
Total number of progeny = 1005 (same as before)
Map distance between F and G = (214 / 1005) * 100 = 21.29 mn (rounded to the nearest whole number)
Interference Coefficient:
Interference coefficient is not provided in the given data.

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Answer:

44

Explanation:

Work = Force X Distance

Answer: Friction is the resistance to motion of one object moving relative to another. For example, when you try to push a book along the floor, friction makes this difficult. Force: Force is essentially a push, or a pull action, that can lead to certain outcomes.

Answer:

v=10.78 m/s

Explanation:

Given that,

The student estimates that  the apple traveled 1.1 seconds straight down to the ground. We need to find the maximum velocity of the apple before it hit the ground. The initial velocity of the apple is equal to 0 as it was at rest. It will move under the action of gravity.

Using equation of motion to find it as follows :

v=u+at

a = g

⇒v=gt

v=(9.8 m/s²) × (1.1 s)

v = 10.78 m/s

So, the maximum velocity of the apple is 10.78 m/s.

Answer:

A

Explanation:

Answer: Polish creates a thin layer of wax on the surface of the leather which protects the leather from getting wet and undergoing wear and tear. It also has a lubricating effect on the leather keeping it supple and preventing the leather from drying out and cracking

The direction to paddle straight across the harbour would be directly east, at a heading of 90 degrees measured north of east.

The direction to paddle would be directly east, with a heading of 90 degrees measured north of east, to proceed straight across the harbour. Accordingly, the paddler must direct their craft or themselves towards the horizon's point that is 90 degrees to the right of true north.

The paddler should be able to traverse the harbour by keeping to this heading without getting carried away by the wind or currents. To guarantee safe and efficient travel, it is crucial to check the weather and tides in advance.

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Answer:

1.3 Pa

Explanation:

from general gas equation

p1v1/TO =P2V2/T2

We can use the thin lens equation to relate the distance of an object to its image formed by a lens. The thin lens equation is:

\(1/f = 1/d_o + 1/d_i\)

where:

f is the focal length of the lens

d_o is the distance from the object to the lens

d_i is the distance from the lens to the image

Let's assume that the height of the mountain is h, and the height of the image on the camera sensor is h'. Then, the ratio of the height of the mountain's image on the camera's image sensor for the second picture to its height on the image sensor for the first picture is:

\(h'_2/h'_1\)

We can use similar triangles to relate the object and image distances to the heights of the object and its image. The ratio of the heights is equal to the ratio of the image distance to the object distance:

\(h'/h = d_i/d_o\)

For the first picture, the object distance is d_o = 12 km = 12000 m, and the image distance can be found using the thin lens equation:

\(1/f = 1/d_o + 1/d_i\)

Solving for d_i, we get:

\(1/d_i = 1/f - 1/d_o\)

\(d_i = 1 / (1/0.050 - 1/12000)\)

\(d_i = 0.05 m\)

The ratio of the heights for the first picture is:

\(h'_1/h = d_i/d_o = 0.05m / 12000 m\)

\(h'_1/h = 4.16 \times 10^{-6}\)

For the second picture, the object distance is d_o = 5.8 km = 5800 m, and the image distance can be found using the thin lens equation as before:

\(1/f = 1/d_o + 1/d_i\)

\(1/d_i = 1/0.05 - 1/d_o\)

\(d_i = 0.05 m\)

The ratio of the heights for the second picture is:

\(h'_2/h = d_i/d_o = 0.05 mm / 5800 m\)

\(h'_2/h = 8.62 \times 10^{-6}\)

So the ratio of the height of the mountain's image on the camera's image sensor for the second picture to its height on the image sensor for the first picture is:

\(h'_2/h'_1 = (h'/h)_2 / (h'/h)_1\)

\(h'_2/h'_1 = (8.62 \times 10^{-6}) / (4.16 \times 10^{-6})\)

\(h'_2/h'_1 = 2.07\)

Therefore, the ratio of the height of the mountain's image on the camera's image sensor for the second picture to its height on the image sensor for the first picture is approximately 2.07.

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Given,

The work done on the spring, U=320 J

The spring constant, k=730 N/m

The work done on the spring is stored in it as the spring potential energy. And it is given by

On rearranging the above equation,

On substituting the known values in the above equation,

Thus the spring stretches for 0.94 m. Therefore the correct answer is option 4.

Answer:

C book sitting on a shelf.

Explanation:

An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position

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Answer:

the second one

Explanation:

Particle motion increases when solid particles are added to the system.

The possible valid accesses for an array a and vector v, each with 10 elements is given below:Array: a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9]Vector: v[0], v[1], v[2], v[3], v[4], v[5], v[6], v[7], v[8], v[9]

The term array is used to define a set of similar data types that are stored in contiguous memory blocks. The index of an array starts at 0, which means the first element of the array is stored at index 0. In the case of arrays, the elements must be of the same data type.The term vector is defined as a dynamic array, which means that the size of the vector can be changed during runtime. Vectors are defined in the same way as arrays, except that they have a dynamic size limit and can be easily resized.

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Answer:

The electrons come from the free electrons in wool which contains moisture or other forms of additives that creates impurity centers which causes the wool to be electrically conductive

Explanation:

Wool which is mixed with certain substances, conducts electricity in a manner similar to the wool-water system that give rise to centers of impurities where electrical conduction takes place

The ability to conduct electricity is related to the presence of free electrons on a material. Therefore, when a balloon, which is an insulator, is rubbed with wool, some of the mobile electrons on wool, which is also an insulator without the presence of substances that aid its electrical conductivity, are transferred to the balloon, thereby making the balloon to be negatively charged

Answer:

ans a

Explanation:

On a velocity - time graph, if the line crosses the x - axis it depicts that the object has started moving in the opposite direction.

Answer:

metal conducts heat faster than wood. which means the metal conducted heat away from your hand (or whatever it is) faster than wood.

Explanation:

just because they feel warm/cold doesn't always mean that it is warm/cold. if they both were sitting at room temp for a long time, then both will eventually reach the temp of the room. even though they are the same temp the metal will feel colder than the wood because of the thermal conductivity of the metal compared to the wood.

The different thermal conductivities of metal and plastic are important in the design of the bowl is metal conducts heat faster than Plastic. which means the metal conducted heat away from your hand (or whatever it is) faster than Plastic.

Thermal conductivity can be defined as the degree to which heat is transmitted through the cross-section of the unit of an object, where the temperature exits directly across the surface.

Electrical conductivity is a measure of how much energy (moving charge) can pass through objects under the influence of a used electric field. Thermal conductivity measures how heat (heat moving energy) can pass through objects below temperature differences.

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The approximate period in years for Neptune to orbit the sun is 165 years.

To find the period in years, we can use Kepler's Third Law, which states that the square of the period in years is equal to the cube of the average distance in AU. In mathematical terms, this can be written as:

P^2 = D^3

Where P is the period in years, and D is the average distance in AU.

Plugging in the given values, we get:

P^2 = 30^3

P^2 = 27,000

Taking the square root of both sides, we get:

P = 165

Therefore, the approximate period in years for Neptune to orbit the sun is 165 years.

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Answer:

white

Explanation:

This experiment causes lines of different colors because the constructive interference depends on the wavelength, so for different wavelength, the position of the maximum will be different.

Now, in diffraction fo a single slit we always have a central maximum (for all the colors)

This means that after the diffraction, we will have that all the colors have a maximum in the center, which will produce white light again, then the color of the central image is white

Answer:

stars #3

Explanation:

they didn't know it was stars